A Q-based approach to clausal ellipsis: Deriving the preposition stranding and island sensitivity generalisations without movement

This paper argues that the meaning of a clausal ellipsis site can only be recovered from a syntactically derived question, regardless of whether this question is explicitly uttered or is merely pragmatically inferred. This entails that the meaning of a clausal ellipsis site cannot be recovered from an inferred question q in a language L if q is syntactically ill-formed in L. I demonstrate that this restriction on recoverability can account for Merchant’s (2001; 2004) Preposition-Stranding Generalisation and for the observation that fragments appear to be sensitive to syntactic islands (Merchant 2004; Abels 2011; Barros et al. 2014; 2015) without any mention of whether remnants of clausal ellipsis themselves undergo movement. Because there is no need to stipulate that remnants themselves undergo (often exceptional) movement under this approach, a theory of clausal ellipsis modelled on Cable’s (2010) Q-based analysis of wh-questions is developed that permits non-pronunciation “around” designated phrases. This approach is shown to be preferred on many occasions to the predominant movement-based analysis (Merchant 2004), which is too restrictive and must frequently resort to the notion of ellipsis repair.


Introduction
Due largely to the influence of Merchant (2001;, the dominant contemporary position on fragmentary questions and responses in the Minimalist literature is that they are derived by clausal ellipsis. Clausal ellipsis involves the non-pronunciation of a clause to the exclusion of one or more phrasal constituents. Thus, according to this view, fragments are not generated in syntactic isolation (Ginzburg & Sag 2000;Culicover & Jackendoff 2005; among others), but are remnants of an ellipsis procedure that applies to a clause.
Within this clausal ellipsis framework, Merchant (2004) argues for a unified approach to fragments, according to which all remnants of clausal ellipsis are A-moved to a position that dominates the ellipsis site. On Merchant's approach, interrogative and declarative fragments display the syntax exemplified in (1a) and (1bB) respectively. In examples, small caps represents focal prominence and struckthrough text represents ellipsis.
The cornerstone of Merchant's (2004: 670-673) analysis is the E-feature, which provides instructions to PF and LF about how to generate and interpret clausal ellipsis. The e-feature is borne by a particular syntactic head H and, after Spell-out, instructs the PF component of grammar to render unpronounced the syntactic complement of H (call it "XP"), either by suppressing Vocabulary Insertion (Halle & Marantz 1993) in XP or by triggering a phonological deletion operation that applies to XP, depending on one's favoured conception of PF-operations. Consequently, the e-feature's instruction to PF makes reference to a syntactic constituent, which accords with the foundational assumption that grammatical rules and/or instructions are only well-formed if they make reference to constituents (Winkler 2005: 184). Because the remnant occupies a position that dominates H, the instruction encoded in the e-feature that is received by the PF interface is therefore a simple syncope rule (2). Adopting the position that remnants of clausal ellipsis A-move to SpecHP in English (Thoms 2010: 286;Griffiths & Lipták 2014), this analysis yields the representation in (3) for the fragments in (1), where the boxed phrase is elided.
(2) φ XP → ∅/e__, ( (1a) and (1bB)) The idea that all remnants of clausal ellipsis are displaced in this manner is commonly referred to as the move-and-delete approach to clausal ellipsis (henceforth, the M&D approach).
A minor change to Merchant's analysis, which involves (2) being replaced with the instruction to PF in (4), yields a theory in which remnants remain in the ellipsis site, with non-pronunciation occurring "around" them. (4) where ∅ = non-pronunciation, φ = phonological realisation, Y = a wh-phrase or a focused item ( to be revised) According to (4), the e-feature instructs the PF to suppress Vocabulary Insertion (or undertake deletion) within the maximal projection HP of the head H bearing the e-feature, to the exclusion of any wh-phrases or focused phrases properly contained in HP. Adopting this analysis allows one to posit the representations in (6) for the fragments in (5), where the single-lined boxed phrase is elided, and double-lined boxed phrase is the remnant of ellipsis.
(5) a. (for (5a) and (5bB)) I will refer to this variant of Merchant's (2004) analysis as the in-situ approach to clausal ellipsis. 1 Although the M&D approach and the in-situ approach both view clausal ellipsis as a PF-operation that targets a syntactic constituent (the complement of H [E] or the maximal projection of H [E] ), the M&D approach clearly demands less from phonology. This is because the e-feature in the M&D framework instructs PF to apply deletion (or suppress Vocabularly Insertion) uniformly and unselectively in the ellipsis site, whereas the e-feature in the in-situ framework instructs PF to be selective with regards to how deletion (or suppression) is applied. Conversely, the in-situ clearly demands less from syntax. In the case of English, for example, the in-situ approach does not require A-movement of presentationally focused non-wh phrases to a clause-peripheral position that they cannot occupy in non-elliptical environments in question-and-answer contexts (Ward 1988;Birner & Ward 1998;Breul 2004). Consequently, it appears that one cannot favour the M&D approach over the in-situ approach -or vice versa -on conceptual grounds alone, as one approach is as parsimonious as the other.
Which approach is correct is therefore an empirical matter. Merchant (2001; and others (e.g. İnce 2006;Shen 2017) have observed that, in certain structural configurations, all remnants of clausal ellipsis behave like A-moved items, regardless of whether they can be moved in non-elliptical environments or not. These authors interpret their observations as evidence for the M&D approach, arguing that remnants show properties associated with A-moved items because all remnants must undergo A-movement to escape ellipsis.
For advocates of the in-situ approach, the fact that items that cannot be moved in nonelliptical environments, such as presentationally focused non-wh phrases in English, often show properties associated with A-movement when they are remnants of clausal ellipsis must arise as a byproduct of an exogenous process, one that is independent of A-movement itself.
In this paper, I argue that some of the A-movement properties exhibited by fragments can be attributed to a process other than A-movement itself. The process in question is that of recovering the meaning of the ellipsis site (i.e. semantically licensing clausal ellipsis). My argument, which is presented in §3-4, runs as follows: • As Weir (2017) has recently shown, the explicit and implicit questions (qs) in the set of Questions Under Discussion (QUDs) from which the meaning of a clausal ellipsis site is recovered (Merchant 2004: 687;Krifka 2006;Reich 2007;Barros 2014a;Weir 2014; Barros & Kotek 2018; among others) cannot denote a set of unstructured propositions. These qs must therefore have structured meanings in the technical sense developed by von Stechow (1981) and Cresswell & von Stechow (1982) (see von Stechow 1991 and references in there).
• Structured meanings are the product of syntactic composition. Therefore, all ellipsislicensing qs in the QUD are syntactically generated, regardless of whether they are explicitly uttered or merely implied. • There is no question q available in the QUD to license clausal ellipsis in a language L iff q is syntactically ill-formed in L. If no other well-formed q′ is available in the QUD to semantically license ellipsis in a particular context then the fragment derived from ellipsis, which relies on q for its semantic licensing, is judged to be unacceptable.
Upon adopting this view of how clausal ellipsis is licensed, which I contend is the natural conclusion to draw from Weir's (2017) argument that ellipsis-licensing qs must have structured meanings, it can easily be shown how the restrictions it imposes serve to give the impression that remnants of ellipsis are themselves A-moved phrases. In §2-4 of this paper, I show this for two properties of fragments: their sensitivity to syntactic islands (Abels 2011;Barros et al. 2015; and their systematic ability or inability to strand their selecting prepositions under ellipsis (Merchant 2001;. These two A-movement properties are epitomised by the Preposition-stranding Generalisation and the Island-Sensitivity Generalisation, which are introduced in §2. Both of these properties can be attributed to the semantic recoverability conditions on clausal ellipsis, rather than to the alleged A-movement of remnants (see §3-4). The M&D approach is not automatically invalidated by demonstrating that two of the A-movement properties exhibited by fragments must be attributed to a process other than A-movement, however. All the other A-movement properties of fragments discussed in Merchant (2004) and elsewhere in the literature must be similarly attributed to independent factors before the M&D approach and in-situ approach can be said to have equal explanatory power. This will remain a task for future research. However, I argue in §5 that the in-situ approach will be favoured over the M&D approach on conceptual grounds if this situation ever obtains. This is because the in-situ approach does not require superfluous A-movement and need not appeal to the often untestable notion of "ellipsis repair" to account for (i) the acceptability of fragments that are immovable syntactic items and for (ii) the island-insensitivity of clausal ellipsis in wh-in-situ languages. The paper is summarised in §6. Appended to the paper is a postface which outlines how implicit wh-questions are syntactically accommodated from explicitly-uttered antecedents of ellipsis.

Two A-movement properties of fragments
As mentioned in §1, the two movement properties of fragments I discuss in this paper are epitomised in the Island-Sensitivity Generalisation in (7) and the Preposition-Stranding Generalisation (Merchant 2001; in (8).

(7)
Island-Sensitivity Generalisation In wh-movement languages, when no anisomorphic source for ellipsis is available, remnants of clausal ellipsis with island-bound correlates make for unacceptable fragmentary responses. (8)

Preposition-Stranding Generalisation
When no anisomorphic source for ellipsis is available, a language L will allow "bare" DP fragments that are interpreted as complements of prepositions iff L allows preposition-stranding under regular A-movement.
The next two subsections explain these generalisations and show how the M&D approach can straightforwardly derive them.

The Island-Sensitivity Generalisation
In the ellipsis literature, syntactic isomorphism obtains in clausal ellipsis environments when an elliptical clause (henceforth, a source) and its antecedent have parallel phrase markers. Although it has been claimed that syntactic isomorphism is required to license some forms of ellipsis (Rooth 1992b;Fiengo & May 1994), research has shown that isomorphism is not required to license clausal ellipsis (Merchant 2001;Barros 2014a;among others). Support for this conclusion comes from the observation that isomorphic sources generate unattested readings (9), are ill-formed due to island-violating wh-movement (10-11), or simply cannot be formulated (12) for many clausal ellipsis constructions that are nonetheless judged as acceptable. Such constructions must therefore have syntactically anisomorphic (i.e. not isomorphic) sources.
(9) That's a gazebo. But I don't know who built it or why. Possible sources a. why they built it anisomorphic b. #why I don't know who built it isomorphic (10) They hired someone who speaks a Balkan language -guess which! Possible sources a. which 1 they speak t 1 anisomorphic b. which 1 it is t 1 that they speak anisomorphic c. *which 1 it is that they hired [ island someone who speaks t 1 ] anisomorphic d. *which 1 they hired [ island someone who speaks t 1 ] isomorphic (11) Sue married a tall man, but I don't know how tall.
Possible sources a. [ how tall] 1 he is t 1 anisomorphic b. [ how tall] 1 she married [ island a t 1 man] isomorphic (12) Either something's on fire or Joe's baking a cake, but I don't know which. Possible sources a. which 1 it is t 1 anisomorphic As the Hungarian example from Barros et al. (2015) in (13) shows, clausal ellipsis is prohibited when no well-formed source is available. In this example, the copular clausal source in (13a) is unacceptable because the plural agreement suffix -ak, which obligatorily suffixes to predicative adjectives, is absent from magas, whereas the sources in (13b-13c) are ill-formed because they display island-violating wh-movement.
(13) Hungarian *John ismer néhány magas lányt, de nem tudom milyen magas. John knows some tall girls but not know.1s how tall 'John knows some tall girls, but I don't know how tall. This example from Hungarian exemplifies the Island-Sensitivity Generalisation presented in (7), as the remnant's correlate in the antecedent clause (i.e. magas) is contained in a syntactic island. This generalisation holds across languages, as Abels (2011) and Barros et al. (2014) have shown. With respect to wh-fragments such as milyen magas in (13), the pattern described by the Island-Sensitivity Generalisation is hardly surprising: Hungarian fronts its wh-phrases, and therefore an island-violation is expected when no "island-evading" elliptical source is available. What is surprising is that the Island-Sensitivity Generalisation also holds for non-wh fragments in languages that do not A-move presentational or contrastive foci in standard, non-elliptical environments. This is demonstrated by the English dialogue in (14). In this example, no anisomorphic source for ellipsis is available, as the adjective former cannot be used predicatively (i.e. Buckeye Bill is former is ungrammatical).

(14)
A: I heard Buckeye Bill is the main source of information in this two-bit town. B: *No, former. He's moved away.
(intended: he's the former source of information) The observation that the Island-Sensitivity Generalisation holds for non-wh fragments in English is straightforwardly explained under the M&D approach, which maintains that all remnants of clausal ellipsis, regardless of whether they bear wh-features or not, undergo A-movement to escape ellipsis. Consequently, the only source available for (14B) -i.e. the isomorphic source -violates the Left Branch Condition (Ross 1976), and is therefore ungrammatical: 2 (15) *Former 1 he is [ island the t 1 source of information] in this town. Rodrigues et al. (2009) demonstrate that, in the Spanish example in (16a), the source for clausal ellipsis is the anisomorphic cleft clause in (16b).

The Preposition-Stranding Generalisation
(16) Spanish a. Juan ha hablado con una chica, pero no sé qué chica. Juan has talked with a girl but not know what girl 'Juan has talked with a girl, but I don't know which girl.' 2 Potter (2017) reports the results of four experiments that test the acceptability of fragments with islandbound correlates in English. These experiments are acceptability-judgement tasks undertaken by anonymous participants via Amazon's Mechanical Turk web-platform. Only users with IP addresses originating in the USA could participate. Potter's participants find fragments with island-bound correlates to be acceptable. From this, Potter concludes that the Island-Sensitivity Generalisation is false. Problematically, all of Potter's stimuli involve the island-bound correlate occupying a linearly final position in the antecedent utterance. In this position, all fragments are judged to be acceptable, regardless of whether their correlate in the antecedent clause is island-bound. This is the utterance-final effect (Griffiths & Lipták 2014: 202, footnote 10; Barros et al. 2014), an unexpected phenomenon for which a potential explanation was recently offered by Reeve (2016). Because Potter does not control for this effect, it seems warranted to reject the conclusions he draws and to therefore maintain that the Island-Sensitivity Generalisation is empirically accurate.
b. … [ qué chica] 1 t 1 es la chica con la que ha hablado Juan. what girl is the girl with the that has talked Juan '…which girl is the girl that Juan has talked to.' Because these cleft clauses cannot host the exceptive modifier más 'else' in Spanish (as (17a) shows), its presence in a clausal ellipsis construction such as (16b) makes the cleft source unavailable. When this happens, an unacceptable utterance is generated, as (17b) shows. Unacceptability arises here because no isomorphic source is available, either. Generating the isomorphic source requires preposition-stranding wh-movement, which is forbidden in Spanish (see (17c)).

(17)
Spanish a. *[ qué chica más] 1 t 1 es la chica con la que ha hablado Juan what chica else is the girl with the that has talked Juan 'which other girl is the girl that Juan has talked to' b. *Juan ha hablado con una chica rubia, pero no sé qué chica más. Juan has talked with a girl blonde but not know what girl else 'Juan has talked to a blonde girl, but I don't know which other girl.' c. *¿Qué chica más ha hablado Juan con?
what girl else has talked Juan with 'Which other girl has Juan talked to?' Although no anisomorphic copular clausal or cleft source for clausal ellipsis is available (see (19)) (Merchant 2001: 122), the English counterpart of (17b) in (18) is acceptable. This is because the isomorphic source in (20) is available, due to the fact that English allows preposition-stranding wh-movement.
(18) John spoke with the blonde girl, but I don't know which other girl.
(19) a. *Which other girl was it? b. *Which other girl was the girl that he spoke with?
(20) Which other girl did John speak with?
The contrast observed between English and Spanish exemplifies the Preposition-Stranding Generalisation from (8). When the availability of anisomorphic sources is controlled for, one observes that English (a preposition-stranding language) allows for "bare" DP fragments that are interpreted as complements to P, while Spanish (a language without preposition-stranding wh-movement) does not. With respect to wh-fragments, the pattern described by the Preposition-Stranding Generalisation is again unsurprising: the constraints on wh-movement that (fail to) generate bare DP wh-fragments are also observed in non-elliptical environments. What is surprising is that the Preposition-Stranding Generalisation holds for non-wh fragments in languages that do not A-move presentational or contrastive foci in standard, non-elliptical environments. For instance, English permits DP fragments that are interpreted as complements of P (see (21)), but German, which does not permit preposition-stranding A-movement, does not (see (22)). (Note that the dative case-marking on the German fragment rules out any anisomorphic sources for (22B).)

(21)
German ( The observation that the Preposition-Stranding Generalisation holds for non-wh fragments is straightforwardly explained under the M&D approach, which maintains that all remnants of clausal ellipsis, regardless of whether they bear wh-features or not, undergo A-movement to escape ellipsis. This movement is permitted in English, which permits preposition-stranding, but prohibited in German, which disallows preposition-stranding (in the cases under consideration here, at least): (23) Mary 1 he was talking with t 1 the underlying syntax for (21B) (24) *[dem Hans] 1 sie hat mit t 1 gesprochen the underlying syntax for (22B)

Recovering the meaning of clausal ellipsis
The previous section showed that the M&D approach derives the Island-Sensitivity and Preposition Stranding Generalisations in a straightforward manner. The question I wish to address in this paper is whether the in-situ approach presented in §1 can derive these two generalisations with equal simplicity. To answer this question, I must first discuss how the meaning of clausal ellipsis is recovered. I argue in this section that recent developments in this subfield lead naturally to the idea that clausal ellipsis is always recovered from a syntactically derived question. Once this idea is adopted, and once some technical details associated with this idea are explicated ( §3.2), it can be shown that the in-situ approach derives the Island-Sensitivity and Preposition-Stranding Generalisations as parsimoniously as the M&D approach does ( §4). Ginzburg (1994) defines the Questions Under Discussion (the QUD) as a partially-ordered set that specifies the currently-discussable questions at any point during a conversation. The maximal QUD (MaxQUD) is the most conversationally-prominent discussable question (or unordered subset of questions) in this set, and occupies the topmost position on the pushdown stack. Questions are introduced into the QUD by a number of processes. For instance, asking an explicit question q makes q the MaxQUD, whereas asserting p moves the polar question ?p into the MaxQUD position (Farkas & Bruce 2010; see Ginzburg & Miller 2017 for more ways to add questions to the QUD). In the first case, the MaxQUD is an explicit question, whereas in the second case the MaxQUD contains an implicit question. Adopting a "direct interpretation" approach, Ginzburg & Sag (2000: Chapter 8) argue that the propositional meaning of a fragmentary response is obtained by unifying the fragment with a single question within the (possibly singleton) set of questions that constitutes the MaxQUD. Ginzburg & Sag's theory has been independently recast in Minimalist terms by Krifka (2006), Reich (2007), Barros (2014a), Weir (2014;, and others. In this line of research, which adheres to the notion that fragments are remnants of clausal ellipsis, it is proposed that the meaning of an elided clause is semantically recovered from the meaning of a single question in the MaxQUD. The numerous benefits of appealing to a question in the MaxQUD to recover the meaning of the elided clause, rather than appealing only to the utterance that explicitly antecedes the elided clause, are well-documented in this line of research, and are therefore not repeated here (see Weir 2014 for an engaging overview). Weir (2017) has recently demonstrated that a simple QUD-based recoverability condition such as (25), which states that clausal ellipsis is recoverable in a clause α if the focus semantic value of α and the denotation of a question in the MaxQUD match, is insufficient for capturing the patterns of acceptability found in a number of clausal ellipsis configurations.

(25)
Simple QUD-licensing condition on clausal ellipsis (to be discarded) Let α be a clause to which ellipsis applies, and let q be a question in the MaxQUD. Ellipsis is recoverable iff ⟦q⟧ = ⟦α⟧ f .
Weir's evidence comes from comparing questions such as those in (26) and (27) below. On a standard "propositional-set" view of questions and focus, which uses Hamblin/Rooth alternatives, these questions denote the same sets of sets of possible worlds. In other words, they are cointensional. This is because the set of worlds in which the machine sends two signals (for instance) is the same set of worlds in which it sends the signal twice. From a propositional-set viewpoint, the focus semantic values for the answers in (26) and (27) are cointensional in precisely the same way.
(26) A: How many signals did the machine send? a. B: It sent two signals. b. B: It sent a signal twice.

(27)
A: How many times did the machine send a signal? a. B: It sent two signals. b. B: It sent a signal twice.
Because the questions in (26) and (27) are cointensional, and because their answers are cointensional too, the simple recoverability condition in (25) predicts that clausal ellipsis is recoverable in each of the answers. This prediction is not borne out. Only the cardinal fragment may answer the question in (26), and only the multiplicative adverbial fragment may answer the question in (27), as the examples in (28) and (29) show. Having convincingly shown that one cannot appeal to morphosyntactic constraints to explain the unacceptability of (28b) and (29a), Weir concludes that the recoverability condition in (25) is inadequate.

(28)
A: How many signals did the machine send? MaxQuD a. B: Two signals. b. B: *Twice.

(29)
A: How many times did the machine send a signal? MaxQuD a. B: *Two signals. b. B: Twice.
Weir argues that the contrast observed in (28) and (29) can only be captured by a recoverability condition on clausal ellipsis that is formulated in the Structured Meaning approach to questions and focus. In this framework, questions are viewed as simple functions that yield type-t expressions when applied to their answers. Both questions and statements containing foci are structured propositions that are arguments of speech-act operators such as quest(ion) and ans(wer) (Reich 2002;Krifka 2006), as shown in (30) and (31). In these representations, the last member of the ordered set is the background, while those members that precede the background are collectively known as the focus. These representations are known as focus-background structures. Adopting the Structured Meaning framework, the recoverability condition that Weir offers is reproduced in a modified form in (32). 3 Unlike (25), which makes reference to the meaning of the entirety of the question that constitutes the MaxQUD and the entire elliptical clause, this condition makes reference only to meaning of their backgrounds.
(32) Background-matching condition on clausal ellipsis Given a question q in the MaxQUD with background Q and a clause α with background A, clausal ellipsis is recoverable in α iff A ⊑ Q.
Now consider the focus-background structures for the utterances in (28) and (29), which are given in a simplified form in (33) and (34) below. In (33), only the background of the first answer matches with the background of the MaxQUD. Conversely, only the background of the second answer matches with the background of the MaxQUD in (34). Therefore, according to Weir's condition, clausal ellipsis is only recoverable in these matching configurations. As the data in (28) and (29) have already shown, this is correct.
λx. the machine sent x signals⟩) b. B: ans(⟨twice, A, λt. the machine sent a signal at interval t⟩)

(34)
A: quest(⟨time, λx. the machine sent a signal at interval t⟩) MaxQUD a. B: ans(⟨two, A, λx. the machine sent x signals⟩) b. B: ans(⟨twice, A, λt. the machine sent a signal at interval t⟩) Ginzburg & Sag (2000), Barros (2014a), and Weir (2014) argue that indefinite expressions invoke implicit wh-questions that enter the MaxQUD. This means that the assertions in (35A) and (36A) invoke implicit MaxQUDs that are equivalent to the explicit questions in (28) and (29) respectively. Because the pattern of ellipsis licensing observed in (36-35) is the same as the one in (28-29), one must conclude that the implicit questions that license clausal ellipsis also have structured meanings.

(35)
A: I heard that the machine sent a certain number of signals. a. B: Yes, two signals. b. B: *Yes, twice.

(36)
A: I heard that the machine sent a signal a certain number of times. a. B: *Yes, two signals. b. B: Yes, twice.
At this point, the question arises about the how implicit questions that license clausal ellipsis come to have meanings that are structured. There are two options: either these questions are linguistically derived but unpronounced, or they are not linguistically derived and our domain-general conceptual structures (i.e. Mentalese) are complex enough to mimic focus-background structures. Although the latter option is pursued in other frameworks (e.g. Dynamic Syntax with the Type Theory of Records), I suggest that the former option is better suited to Minimalist approaches to fragments, following (Reich 2004: §5.2). This is because these approaches analyse fragments as remnants of ellipsis, which has been characterised as a surface anaphor (Hankamer & Sag 1976). This characterisation can be maintained if the implicit questions that license clausal ellipsis are viewed as linguistically -i.e. syntactically -derived. For ease of reference, let us refer to this idea as the QUD-syntax Correspondence conjecture: QUD-syntax Correspondence conjecture Regardless of whether they are explicit or implicit, the questions in the MaxQUD from which the meaning of clausal ellipsis is recovered are always syntactically derived. 4,5 As I show in §4, the main consequence of adopting (37) is that one can use it to derive the Island-Sensitivity and Preposition-Stranding Generalisations without appealing to M&D-style mechanisms. 6 Before doing this, I will first outline how pied-piping can be 4 Importantly, the characterisation of clausal ellipsis as a surface anaphor and the conjecture in (37) only apply to what Merchant (2004: 716) calls "true" fragmentary utterances. They do not apply to idiomatic fragments such as departure expressions (e.g. later, until next time, or the fictional under his eye) or to "discourse initial" fragments such as (iB) below. Although discourse initial fragments are derived via clausal ellipsis of a copular clause, the only meaningful missing element -the pronoun -can be recovered through non-linguistic association with a salient individual in the world (see Barros 2014a for a more precise formulation of this idea). As a comparison of (iB) and (iB′) shows, only the pronoun and the semantically-vacuous copula can be elided in discourse initial cases. 5 Although the meaning of clausal ellipsis is recovered from a syntactically derived question, the recovery process itself must be semantic/pragmatic in nature. Under the assumption that the topmost position in the QUD-stack can be occupied by an unordered set of questions (see the introductory paragraph of this section), evidence for the semantic/pragmatic nature of the recovery process comes from the observation that when more than one question is maximal in the QUD, an elided clause can be semantically ambiguous (as in (i), where clausal ellipsis can be recovered from either implicit question). The semantic/pragmatic nature of the recovery process is also exposed in the dialogue in (ii). In this scenario, the interpretation of the ellipsis site as a unification of the meanings of the implicit questions invoked from A arises from the fact that both questions have the same focus-background structure. Clausal ellipsis is recovered from one of the implicit questions (let us say the first one, for the sake of concreteness) and the meaning of the second question then instils itself into the meaning of the ellipsis site by semantically/pragmatically "piggybacking" on the first question (see Messick et al. 2016 for a formalisation of this idea).
(i) A: John told me that Pete is going to Berlin. qs in QUD after A: When did John tell you that? B: Really? When? When is Pete going to Berlin?
(ii) A 1 : Jack wants apples and Jill wants pears. qs in QUD after A 1 : How many apples does Jack want? B: How many?
How many pears does Jill want? A 2 : Six apples and four pears. 6 Even though it has a long history (see Fiengo & May 1994: 190-193 for an early discussion and Chung et al. 2011 for a more recent one), I am aware that the QUD-syntax Correspondence conjecture is not aligned with the current orthodox stance on the syntactic status of implied questions on the QUD-stack. For instance, Roberts (2012: 8), whose seminal paper arguably popularised the QUD-approach within the broader Minimalist framework, says that "a move in a discourse game is essentially semantic. A question is not necessarily realized by a speech act but is only a question denotation in the technical sense that it proffers a set of relevant alternatives which the interlocutors commit themselves to addressing". Similarly Farkas & Bruce (2010) suggest that "implicated content is on the table, but […] only literal content is associated with syntactic material". Although the conceptual advantage of treating implied questions as a discourse strategy is clear (as no syntax is required), I know of no empirical reasons to favour this treatment. This paper aims to show that there are benefits to treating implied questions -at least those implied questions that serve to license clausal ellipsis -as syntactically derived. In this respect, this paper indirectly represented in the Structured Meaning framework, so that Weir's Background-matching condition from (32) can be straightfowardly employed in configurations where piedpiping is observed.

Representing pied-piping in the Structured Meaning approach
In order to apply Weir's Background-matching condition in configurations that display pied-piping (which will be necessary for deriving the Preposition-Stranding Generalisation in §4), I must develop a Structured Meaning approach of pied-piping. To accomplish this, I adopt Cable's (2010) approach to pied-piping and translate his "Q-based" theory into the Structured Meaning framework. Cable's Q-based theory of pied-piping is a reflex of his theory of wh-questions. Cable argues that wh-phrases must be c-commanded by a Q-particle, which is phonologically realised in many of the world's languages but is null in English. I rename the Q-particle as the f-particle here, as I will shortly put the Q-particle -or rather, the semantic choice function introduced by the Q-particle at LF -to work in both questions and assertoric utterances that display foci. In wh-movement languages such as English, it is the maximal projection of the f-particle (i.e. fP) that undergoes wh-movement, as shown in (38) below. From a semantic perspective, Cable views wh-words as having a focus semantic value but as having no ordinary semantic value, following Beck (2006). In other words, he views wh-words as introducing a set of Hamblin-alternatives. Through Pointwise Function Application (Hamblin 1973), this set of alternatives must become large enough to provide a focus semantic value for the syntactic sister of the f-particle. As already mentioned, the f-particle itself is treated as a choice function, which is any function that chooses a member from a non-empty set. This choice function takes the focus semantic value of its syntactic sister as its argument. For Cable, the choice function introduced by the f-particle is a variable, which is existentially-bound from the periphery of an interrogative clause. This existential binding is effectuated by the syntactic head Force Q , which also introduces a λ-binder for the proposition and hence derives a question meaning. Putting these ideas together and incorporating them into the standard propositional-set approach to interrogatives yields the meaning in (39) Cable (2010) suggests that English fPs in matrix interrogative clauses undergo A-movement to SpecFocP.
Because the ellipsis literature typically adopts that position that English wh-question formation involves A-movement to C, I choose to use the traditional "CP" label for this projection.
Notice that the wh-phrase is sister to the f-particle in (38). Because it is fP rather than the wh-phrase itself that undergoes A-movement to form questions in English, a pied-piping configuration is generated whenever the f-particle is sister to larger phrase containing the wh-phrase, as (40) shows. For our purposes, we can take the view that the semantic formulae in (39) and (41) therefore differ only with regards to the size of the choice function's argument. Put differently, the set of individual concepts derived through Pointwise Function Application is larger in (41) than in (39). As Cable (2010: Chapter 2) makes clear, an important benefit of this analysis is that it renders LF-pied-piping mechanisms superfluous, as (39) and (41) From a syntactic perspective, Cable assumes that f and C Q must enter into syntactic Agree relation (Chomsky 2001) in wh-questions, which is represented by a dashed line in (38) and (40). Because f selects for its complement in wh-questions in English and wh-movement is overt, this triggers the overt A-movement of fP to SpecCP. We may therefore understand wh-movement in English as arising from the fact that C Q bears an EPP feature (Chomsky 2000: 102). Because A-movement cannot occur over island boundaries, this encodes the island-sensitivity of English wh-movement. Note that C Q itself is semantically vacuous (Cable 2010: 79). I will now recast Cable's analysis in the Structured Meaning framework. The reader should be aware at this point that, in order to maintain clarity of exposition and ease of comparison, this recasting mimics Cable's analysis as closely as possible, and therefore utilises Roothian (1985;1992a) Alternative Semantics in a framework that typically eschews it. For a one-dimensional alternative to Cable's analysis that is couched in the Structured Meaning framework, see Reich (2004).
To translate the import of Force Q into Structured Meaning terms, I suggest that Force Q 's introduction triggers the creation of a structured proposition that has the choice function as its focus, and a λ-abstraction over the choice function as its background (following Reich 2002: 175). Thus, our Structured Meaning versions of (39) and (41) are provided in (42). Cable (2010: 201-205) suggests that his analysis can be extended to declarative utterances containing foci. I actualise Cable's suggestion here. Following Reich (2004), I suggest that F-marked items are also semantic arguments to choice functions, and that these choice functions are also introduced via syntax, just as they are in Cable's theory of wh-questions.
To maintain the analogy with wh-questions, I will also refer to the syntactic instantiation of these choice functions as "f-particles". A plausible Structured Meaning representation for the declarative utterance in (43) There is a notable syntactic difference between (43) and (38): fPs in assertoric responses are adjuncts in English (reflecting the adjunct status of the so-called squiggle operator from Rooth 1992a; see Reich 2002;, 8 whereas fPs in wh-questions take a phrase containing the wh-phrase as its complement. 9 Aside from the larger structured proposition being the argument to a different speech-act operator (i.e. ans(wer), which is introduced by Force A , rather than quest(ion), which is introduced by Force Q ), the main semantic difference between (44) and the formulae in (42) is that the choice function in (44) is constrained. f Pete is the constant function that, when applied to the set represented by its argument, chooses Pete from the set. This allows for the correct ordinary semantic value to be retrieved for (44), as such values are retrieved from structured propositions by applying the background to the focus (i.e. ⟨α, β⟩ = β(α)). For a detailed discussion of how choice functions can be constrained in this manner without recourse to syntactic movement of the focused phrase, see Reich (2004).
Just as the f-particle in questions is not required to take a wh-phrase as its direct complement (see (40)), the f-particle in assertoric responses is not required to directly adjoin to a complement in English wh-questions (Cable 2010: 201-205). Furthermore, Foc in Hungarian bears an EPP feature and therefore overt A-movement occurs, which displaces fP and the phrase it selects to SpecFocP. This movement is sensitive to islands. With regards to English, Kratzer (1991) famously argued that focus is insensitive to syntactic islands. In the current framework, this amounts to arguing that Foc and f do not enter into an Agree relation in English assertoric responses. This claim has been indirectly challenged by Tancredi (2004), Krifka (2006), Wagner (2006), Griffiths & Lipták (2014), Erlewine & Kotek (2016) and others, and has been directly challenged recently by Erlewine & Kotek (2018 a presentational or contrastive focus. The declarative counterparts of a pied-piping configuration, which are known as Focus Phrase configurations (Drubig 1994), are generated in such circumstances. According to our simple Structured Meaning treatment, the presentational Focus Phrase configuration in (45)

w′) in w′})](w) in w⟩)
The Structured Meaning-style formulae presented above are admittedly rather complicated. For clarity's sake, I will therefore use simplified notations whenever possible in the rest of this paper. Henceforth, constraints on choice functions are omitted, as are the restrictors for foci and wh-phrases. λ's are also removed. Thus, structures without pied-piping are represented as in (47a), whereas structures with pied-piping are represented as in (47b).
By recasting Cable's (2010) theory in Structured Meaning terms in §3.2, I have now extended Weir's (2017) analysis to pied-piping and Focus Phrase configurations. The most useful outcome of this exercise is that one can now identify a common property shared by wh-questions and their responses, which is that each displays an fP. Furthermore, the utilisation of fP allows for a more accurate PF instruction for clausal ellipsis to be formulated. Recall from §1 that the rule for selective pronunciation (see (4)) specified that, in an elided clause, a designated phrase Y containing a wh-phrase or a focused element can be pronounced. One can now identify this designated phrase more accurately: The distribution of the e-feature for English clausal ellipsis can also be specified now: it is optionally borne by Force Q and Force A . 11 Resultantly, a more accurate in-situ analysis of the fragments in (1), which is repeated below in (49) Having now introduced a way to represent pied-piping in the Structured Meaning framework, and having now refined the notion of how clausal ellipsis is syntactically licensed under an in-situ approach, the stage is almost set for deriving the Island-Sensitivity and Preposition-Stranding Generalisations without requiring remnants to undergo exceptional movement from the ellipsis site in §4. However, one final issue must be addressed before we proceed to §4. Because it is novel (to my knowledge), readers receptive to the foundational idea in my analysis -namely that syntactically derived implicit questions can be invoked from explicitly-uttered assertions (see (37)) -might nonetheless be puzzled about what this "invocation" procedure consists in and whether there are restrictions on it.
Although my response to these questions is fully compatible with the current ellipsis literature and therefore wholly unsurprising to ellipsis specialists, expounding it is too space-consuming and tangential to this paper's main aim, which is merely to derive the two generalisations from §2 using an in-situ approach to clausal ellipsis. Because of this, I choose to address these questions in an appendix to this paper. Stated very briefly here, 11 I must emphasise that the main text only specifies the syntactic distribution of the e-feature for English. For Hungarian (for instance), the syntactic distribution of the e-feature is different: it is borne by Foc and has an EPP specification, licensing clausal ellipsis only when SpecFocP is occupied. This accounts for two important differences between English and Hungarian. The first is that the remnant of English clausal ellipsis cannot be accompanied by a complementizer, which is generated in CP (i.e. below ForceP but above FocP in both languages), while remnants of clausal ellipsis in Hungarian can. The second is that, while English clausal ellipsis is only permitted in interrogative clauses or (embedded) assertoric clauses (see Temmerman 2013), which are necessarily headed by ForceP, Hungarian clausal ellipsis is permitted in a broader range of clauses, including clausal complements of factive verbs and in relative clauses. See van Craenenbroeck & Lipták (2006) and Lipták (2015) for detailed discussions of Hungarian clausal ellipsis. 12 It is worth mentioning that the in-situ approach derives Merchant's (2001: 67) Sluicing-COMP generalisation (see (i)) straightfowardly, as no non-operator material in COMP is sister to f (see has in (ii) below).
(i) Sluicing-COMP generalization: In sluicing, no non-operator material may appear in COMP. the response given in the appendix runs as follows: "invocation" consists in the listener accommodating an implicit question when confronted with a fragmentary response which has a non-erotetic explicit antecedent. This accommodation procedure is syntactically specified (Fox 1999;Thoms 2013;, and can perhaps be identified as Arregui et al.'s (2006) recycling procedure. Ignoring some important details, the accommodation procedure is constrained such that: (51) i. Aside from its fP projection, an implicit wh-question cannot contain any morphosyntactic ROOTS that are not also present in the explicit antecedent (see Rudin 2018 and references therein). ii. Any pronoun present in the implicit wh-question must co-refer with a phrase in the explicit antecedent (cf. Vehicle Change, Fiengo & May 1994: 218).
Because the implicit questions discussed in the upcoming sections are either syntactically isomorphic to explicit antecedents from which they are invoked or are anisomorphic copular clausal questions that obey the constraints listed above, this partial clarification of what it means to "invoke a syntactically derived implicit question" is sufficient for current purposes. Readers interested in this aspect of the current framework are directed to this paper's appendix for further discussion.

The Preposition-Stranding Generalisation without A-movement
If the QUD-syntax Correspondence conjecture is correct, and if one adopts the idealistic position that only syntactically well-formed structures in a particular language L can be used to advance the conversation in L (i.e. if one ignores performance errors), then a question q can only be in the MaxQUD in L if q is syntactically well-formed in L. This idea is the driving-force behind deriving the Island-Sensitivity and Preposition-Stranding Generalisations without reference to syntactic movement from within the ellipsis site. In this subsection, I derive the Preposition-Stranding Generalisation. Cable (2010) offers a number of restrictions on the syntactic position of fP. One relevant restriction is that fPs cannot be interveners to selection by functional heads. This is encapsulated in his fP-intervention condition, which is presented in (52). 13 (52) fP-intervention condition (Cable 2010: 57) An fP cannot intervene between a functional head X and a phrase selected by X.
At first glance, the preposition-stranding wh-question in (53) appears to violate the fP-intervention condition, as fP intervenes between DP and P that selects it before A-movement occurs. Adopting ideas from Abels (2003), Cable (2010: 111) argues that the fP-intervention condition is actually satisfied in (53) Note also that only f-particles that select for complements, such as the version of the f-particle used to form wh-questions in wh-movement languages (see (38) and (40)), are sensitive to this condition. This is because only complement-taking f-particles will ever disrupt syntactic selection. By their nature, f-particles that are adjuncts, such as the version of the f-particle that is used to form assertions containing narrow foci in English (see (43) and (45)) or wh-questions in wh-movement languages (see §5.2), never disrupt syntactic selection. See Cable (2010: 103) for an emerging typology of f-particles.
According to the QUD-syntax Correspondence conjecture, this means that (53) can serve as the MaxQUD, and can therefore license clausal ellipsis in a clause whose background matches with the background of (53). The question in (53) is the MaxQUD in the dialogue below. In this case, clausal ellipsis is licensed because the background of the MaxQUD and the background of the elliptical utterance match, as (55)  According to the QUD-syntax Correspondence conjecture, this means that (56) cannot serve as the MaxQUD. It is syntactically ill-formed, and is therefore not used in conversation. Consequently, ellipsis cannot be licensed in any clause that depends on (56) for satisfying Weir's Background-matching condition, as (56) is simply absent from the QUD. Because B's response in (57) does indeed depend on (56) being the MaxQUD for its ellipsis site to be semantically recovered, ellipsis is judged to be unacceptable in (57B). Note that the meaning of the ellipsis site in (57B) cannot be recovered from the pied-piping whquestion that is the MaxQUD because the background of this question and the background of (57) do not match, as (58)  This QUD-based explanation for the contrast observed between English and German is fully extensible, and therefore derives the Preposition-Stranding Generalisation without reference to movement of the remnant. Non-P-stranding languages cannot generate syntactically well-formed P-stranding wh-questions, and therefore such questions cannot serve as MaxQUDs. Clausal ellipsis cannot be recovered from a question that is not in the QUD, and consequently an elided clause whose meaning can only be recovered from an ill-formed (and therefore "QUD-absent") P-stranding question is judged to be unacceptable.
Before moving on, there is slightly more to say about the English P-stranding data. Recall from §3.2 that, according to Cable's (2010) theory, two utterances u and u′ pick out the same (sets of) sets of possible worlds if they only differ in how much pied-piping they display. I take this to mean that, if a question q is added to the QUD, all syntactically well-formed pied-piping equivalents of q are simultaneously added to the QUD. This allows us to capture mismatch cases in which pied-piping of P occurs in the explicit question but not in the response (see (59)) or vice versa. This is because the explicit question in (59A) invokes the syntactically well-formed implicit P-stranded question who did Peter speak with?, whose background may serve as the antecedent for clausal ellipsis in (59B).

(59)
A Mismatches are disallowed for some speakers of English when an elided wh-question has an explicit wh-question antecedent, however, as the examples in (60) show. I suspect that this restriction is pragmatic in nature, as such wh-fragments function as verbatim repetitions of the antecedent question. This observation is encapsulated in the rule in (61).

The Island-Sensitivity Generalisation without A-movement
When coupled with the QUD-syntax Correspondence conjecture, the in-situ approach captures the Island-Sensitivity Generalisation straightforwardly. To see this, consider the dialogue in (62) below. After B answers with yes in (62), which moves the propositional content of A's assertion the company wants to hire a hard worker into the Common Ground (Stalnaker 2002 14 In reality, the situation described in the main text only obtains in dialogue situations, i.e. when the antecedent is articulated by speaker A and speaker B responds with a fragment. In monologue situations, in which the antecedent and the elliptical clause share a sentence uttered by the same speaker, the propositional content p of the antecedent will occupy the Local Context (Karttunen 1974)  We observe that (62a-c) are available as fragmentary responses to (62A), each licensed by a different implicit question. Conversely, the fragment in (62d) is not available as a fragmentary response because there is no question in the QUD available to license it. The only question that could license (62d), which is given in (62ii), is syntactically ill-formed in English, and is therefore unsuitable for use in conversation. This example illustrates that a fragment with an island-bound correlate and for which no anisomorphic source is available is unacceptable because no question is available in the QUD to semantically license it. Thus, English non-wh fragments are indirectly islandsensitive: this "island-sensitivity" arises as an epiphenomenon. Such fragments do not themselves cross island boundaries.

An additional constraint on adding questions to the MaxQUD: The case of contrastive fragments
Up to this point, this paper has focused solely on one restriction on adding syntactically derived implicit questions to the MaxQUD, which is the requirement that such questions be syntactically well-formed. There are of course other constraints on adding questions to QUD; ones which apply to all questions, regardless of whether they are syntactically derived or not. In this subsection, I wish to slightly complicate the current analysis by demonstrating how the syntactic requirement on ellipsis-licensing implicit questions and a more general constraint on the composition of the QUD can interact to further restrict the availability of clausal ellipsis in island contexts. The general pragmatic constraint I wish to focus on, which is taken from Barros (2014b) and formulated in (63) as the Corrective QUD constraint, is triggered when the propositional content p of an assertion is denied entry into the Common ground, which occurs after a speaker utters a negative expression such as no or provides a non-linguistic indication of refutation. This constraint affects the QUD and demands that (i) the MaxQUD be reduced to a singleton set of questions q, and (ii) that ⟦q⟧ be the set of propositions which are the focus-alternatives to the rejected proposition p, where this set of alternatives excludes p itself. The Corrective QUD constraint in (63) therefore aims to capture the intuition that speakers often consider each other's proposals to update the Common Ground in need of amendment before they can be accepted, and that speakers provide their corrections via proffering a fresh answer to the explicit or implicit wh-question that the original "incorrect" assertion aimed to answer (Merchant 2004:687;Barros 2014b), where this original question is updated to exclude the propositional content of the "incorrect" assertion as a possible answer. In cases where the original assertion contains a narrow-focused item (see B's utterance in (64)), it is clear what the original question was. Otherwise F-marking can be pragmatically accommodated, i.e. applied retrospectively by the listener. In such cases, the Corrective QUD constraint can be satisfied varyingly, depending on where F-marking is retrospectively applied (see T 3 in (65) for three possibilities). In the dialogues below, T 1 , …, T n represent discrete points in conversational-time.

(63)
Corrective QUD constraint Let q be a question and p be a proposition such that ⟦q⟧ and alt(⟦p⟧) are identical, where ⟦p⟧ o ∈ ⟦p⟧ f \ alt(⟦p⟧). After p is denied entry into the Common Ground, the MaxQUD must be set the singleton of questions {q}.
(64) Context: Sally, Judy, and Rob were the three teaching assistants in the department. Because addressing the MaxQUD is preferred but not required in non-elliptical environments, the singleton MaxQUD formed by applying the Corrective QUD constraint need not be answered immediately (it is answered at T 5 in (66): B's preceding assertion at T 4 contains the contrastive topic Frank and therefore addresses a superquestion), if at all (see (67)). The Corrective QUD constraint is therefore only truly impactful in elliptical environments, where it must be satisfied for clausal ellipsis to be licensed, as I will show momentarily.
(66) T 1 | A: She swore at John's mother last night. T 2 | B: No, T 3 | Speaker B's discourse-move at T 2 triggers the Corrective QUD constraint (i) MaxQUD after T 3 = {she swore at x's mother last night|x ∈ D e } T 4 | B: Frank swore at John's mother. T 5 | B: She swore at Pete's mother.
(67) T 1 | A: She swore at John's mother last night. T 2 | B: No, T 3 | Speaker B's discourse-move at T 2 triggers the Corrective QUD constraint (i) MaxQUD after T 3 = {she swore at x's mother last night|x ∈ D e } T 4 | B: that's not true. T 5 | B: But another rumour I heard about her is that she often … As mentioned already, the Corrective QUD constraint affects all questions, including the syntactically derived implicit questions from which the meaning of clausal ellipsis is recovered. This means that, when the Corrective QUD constraint is triggered, a syn-tactically derived implicit question can only be added to the MaxQUD if it satisfies this contraint. Coupled with the requirement that they be syntactically well-formed, this additional constraint on adding implicit questions to the MaxQUD therefore reduces the likelihood of there being a question in the MaxQUD from which clausal ellipsis can be recovered. This gives rise to the prediction that fragmentary responses which are licensed after the Corrective QUD constraint applies (so-called contrastive fragments, see Griffiths & Lipták 2014) are harder to license than fragments uttered in non-corrective contexts (presentational fragments). As is well-known, this prediction is borne out for fragments with island-bound correlates: many contrastive fragments with island-bound correlates are judged as unacceptable even though their presentational counterparts are perfectly licit, as a comparison of (68B) and (69B) shows (Merchant 2001;Griffiths & Lipták 2014;Barros et al. 2014; among others).

(68)
Context: There is a rumour going around that one of the teaching assistants was fired. The reason why it is contrastive fragments with island-bound correlates in particular that are affected is because the Corrective QUD constraint and the well-formedness constraint on syntactically derived implicit questions introduce conflicting demands that are especially difficult to satisfy simultaneously in island contexts. On the one hand, clausal ellipsis cannot be recovered from an implicit question which is isomorphic to the explicit antecedent in configurations where the correlate is island-bound (such a question would be syntactically ill-formed due island-violating wh-movement, and is therefore barred from the MaxQUD); on the other hand, implicit questions which are anisomorphic to the explicit antecedent will typically violate the Corrective QUD constraint. To provide a concrete example of how these two constraints conspire to preclude clausal ellipsis, let us reconsider the dialogue in (68). First, imagine that the syntactically derived implicit question in (70a) is invoked from the explicit antecedent in (68). In this situation, this implicit question satisfies the Corrective QUD constraint, as it has the same denotation as alt(⟦(68A)⟧). Problematically however, (70a) is syntactically ill-formed, is barred from entering the MaxQUD, and therefore cannot serve as a licensor of ellipsis. This entails that the fragment in (68B) cannot be derived from the underlying isomorphic source in (70b). The anisomorphic implicit question in (71a) makes for a suitable licensor of a presentational fragment derived from the anisomorphic elliptical source in (71b). Indeed, (71b) is the underlying source for the acceptable presentational fragment in (69B). Problematically, the question in (71a) cannot serve to license ellipsis in the contrastive environment in (68) even if the fragment in this dialogue were also derived from the short source in (71b), as the question violates the Corrective QUD constraint (see Barros 2014b;Barros et al. 2014: §4.3 for the same conclusion). This is because ⟦(71a)⟧ = {x was fired : x ∈ D e }, whereas alt(⟦(68A)⟧) = {the rumour that x was fired is true : x ∈ D e }. Provided that the wh-phrase is interpreted as contextually restricted to alt(⟦the rumour that Sally F was fired⟧), the implicit question in (71c) satisfies the Corrective QUD constraint, and should therefore make for a suitable ellipsis licensor. Although this question could indeed license the contrastive fragment the rumour that Judy was fired, it cannot license the fragment in (68B), as neither the focus-background structure in (72a) for the potential long source in (70b), nor the focus-background structure in (72b) for the potential short source in (71b), match the focus-background structure in (72c) for the question in (71c), which violates Weir's (2017) Background-matching condition. In short, the constrastive fragment in (68) is therefore judged as unacceptable because there is no suitable implicit question in the MaxQUD to license it. a. ⟨f, the rumour that f(Sally) was fired is true⟩ structured meaning of (70b) b. ⟨f, f(Sally) was fired⟩ structured meaning of (71b) c. ⟨f, f(the rumour that Sally was fired) is true⟩ structured meaning of (70c) It is important to emphasise that the Corrective QUD constraint in (63) only requires semantic equivalence to obtain between a corrective implicit question and the focusalternative value of the explicit antecedent: it does not require that the implicit question and the explicit antecedent share any syntactic similarities (above and beyond the general constraints on invoking implicit questions, which were mentioned briefly in §3.2 and are listed in the appendix). Consequently, implicit questions that are structurally anisomorphic to their antecedents and which satisfy the Corrective QUD constraint (and all other relevant constraints) are predicted to make for suitable licensors of contrastive fragments. This prediction is borne out, even for contrastive fragments whose correlates are islandbound (Barros et al. 2014;contra Griffiths & Lipták 2014). For example, the contrastive fragment in (73aB) is judged as acceptable because the implicit question in (73b) is present in the MaxQUD to license the ellipsis that generates the fragment. This implicit question makes for a suitable licensor not only because it is syntactically well-formed, but also because it satisfies the Corrective QUD constraint. Specifically, the implicit question in (73b) satisfies the Corrective QUD constraint because the pronoun he can be interpreted as an E-type pronoun meaning 'her new boyfriend' (see the appendix for discussion and references). The contrastive fragment in (74aB) is acceptable for precisely the same reason: an anismorphic implicit question containing an E-type pronoun meaning 'the person they hired' is available in the MaxQUD to license clausal ellipsis (see (74b)).  Barros et al. (2014: 37) b. What language does she speak, then? implicit q invoked from (74aA) To summarise: This subsection demonstrated how the specific constraint on syntactically derived implicit questions (namely, that they are well-formed) and a general constraint on the composition of the QUD interact to restrict the licensing of clausal ellipsis. In particular, I showed that the Corrective QUD constraint in (63) serves to restrict the number of possible anisomorphic syntactically derived implicit questions available in the MaxQUD from which clausal ellipsis can be licensed. This can give rise to a situation in which no implicit questions are available to license ellipsis (as in (68a)), but it need not (as in (73a) and (74a)). Thus, this subsection has demonstrated that the complex distribution of purported "island-(in)sensitivity" under clausal ellipsis can be reduced to a byproduct of the constraints on discourse structure. 17

Summary of §4
I demonstrated in this section that the independently motivated QUD-syntax Correspondence conjecture, which is the idea that the meaning of a clausal ellipsis site is always recovered from a syntactically derived question, can be utilised to capture the Preposition-Stranding and Island-Sensitivity Generalisations without resorting to the idea that movement always occurs from within the clausal ellipsis site. 18 Adopting this conjecture therefore provides the required restrictiveness to the in-situ approach to clausal ellipsis but renders the M&D approach to clausal ellipsis superfluous, at least for capturing the Preposition-Stranding and Island-Sensitivity Generalisations.

The in-situ approach: Clausal ellipsis without ellipsis repair
The previous three sections of this paper were devoted to showing that two A-movement properties exhibited by fragments can be explained by appealing to how the meaning of a clausal ellipsis site is recovered, rather than by appealing to notion that remnants of clausal ellipsis necessarily undergo A-movement.
As mentioned in §1, there are other A-movement properties exhibited by fragments that must receive an "in-situ" explanation before the in-situ approach and the M&D approach can be said to have equal explanatory power ( The pragmatic analysis offered to account for the distribution of contrastive fragments in purely assertoric exchanges in the main text extends straightforwardly to the dialogues in (i) and (ii). In the case of (i), I follow Merchant (2004) and Barros (2014b) in assuming that choosing ¬p from polar question proposal {p, ¬p} triggers the application of the Corrective QUD Constraint in (63) over the propositional core of the polar question. The constraint in (63) is satisfied in (i) because the propositional core of the polar question contains a focused item, and therefore an implicit wh-question corresponding in meaning to alt(⟦p⟧) can be formulated (namely, who did Sally swear at last night?). Although the case in (ii) does not involve a negative marker such as no, it should still be classified as contrastive. This because the contrastive topic puppy in the elliptical clause (Mizuno & Erlewine 2017) gives rise to an interpretation of (ii) in which the elliptical clause is understood as a correction of the antecedent. In particular, the elliptical clause is understood as superseding the antecedent clause as the "correct" subquestion to ask from the implicit superquestion which baby animal should John adopt? (Roberts 2012), where the members of the superquestion are sorted into sets according to species (see iii). This superquestion makes for a suitable licensor of clausal ellipsis in (ii), as it corresponds in meaning with alt(⟦which kitten F should John adopt⟧) (Constant 2014;Mizuno & Erlewine 2017) and therefore satisfies the constraint in (63). A-movement properties here, I nevertheless aim to show in the penultimate section of this paper that, should the abovementioned situation ever come to pass, the in-situ approach will be favoured over the M&D approach for conceptual reasons. I concentrate in this section on the notion of ellipsis repair. It is widely known that the M&D approach is too restrictive and therefore frequently undergenerates fragmentary responses. To overcome this problem, advocates of the M&D approach have argued that the phonological process that yields ellipsis also circumvents certain grammatical constraints, and hence repairs otherwise illicit syntactic configurations (Richards 2001;Merchant 2001;Lasnik 2001;van Craenenbroeck & den Dikken 2006;Fox & Pesetsky 2005; van Craenenbroeck 2010; among many others). Because repair only occurs when ellipsis applies, the claim that ellipsis repair exists cannot be easily tested empirically, which is conceptually problematic. I will demonstrate that no appeal to ellipsis repair is required under the in-situ approach to capture the distribution of two classes of fragments for which a repair-based analysis is required in the M&D framework. These classes are (i) immovable fragments in English and (ii) all fragments in wh-in-situ languages.
Being able to explain the distribution of these fragments without appealing to ellipsis repair is the main reason why the in-situ approach has better future prospects than the M&D approach. By design, the M&D approach will never be able to provide falsifiable analyses of the acceptability of immovable fragments in English or of fragments in wh-insitu languages such as Turkish and Japanese. In contrast, "in-situ" explanations of other A-movement properties exhibited by fragments can potentially be fashioned.

Ellipsis repair
Because it maintains that all fragments are derived by A-moving the remnant of clausal ellipsis to clause-peripheral position, the M&D approach predicts that the effects of an application of A-movement in a non-elliptical utterance α should yield the same effects in the fragmentary counterpart to α. This prediction is incorrect for a number of cases, as Weir (2014: 167-173) demonstrates. To provide one example, consider the utterances in (75a) and (75b), which demonstrate that predicate fronting, which is a form of topicalisation, bleeds an inverse scope reading in English. Based on this contrast, the M&D approach predicts that no inverse scope reading is available in the fragmentary counterpart to (75b), which will also involve A-movement. This prediction is incorrect, however. The example in (76) shows that both a surface and inverse scope reading are available for the fragmentary response. 19 19 Although the scopal ambiguity observed in (75a) is retained in its fragmentary counterpart in (76B), the most natural reading of (i), in which negation scopes under regret, is bled under clausal ellipsis: the fragment in (iiB) can only be understood as 'I don't regret telling John anything'. Thoms (2018) claims that (iiB)'s obligatory wide scope reading must arise through exceptional, overt A-movement of the fragment, which therefore supports the M&D approach. The validity of this argument rests on the assumption that negation cannot take wide scope over regret in the non-elliptical configuration in (i). According to my own native-speaker judgements, this assumption is incorrect: negation can take wide scope in (i) if the context is sufficiently rich and there is enough emphasis on nothing (see (iii)), though whether other native-speakers agree with this judgement is currently unknown to me. It is likely that negation must take wide scope in (iiB) so that scopal parallelism (see Romero 1998;among others) obtains between (iiA) and (iiB).
(i) I regret telling him to buy nothing. Secondly, the M&D approach predicts that an illicit application of A-movement in a nonelliptical utterance α should yield an unacceptable fragmentary counterpart to α. This prediction is incorrect for a number of cases. For instance, bare transitive verbs, prepositions, and derivational prefixes are immovable in English topicalisation contexts, as (77) shows. However, such items make for suitable fragments, as (78) shows. 20,21 (77) a. *John wants to revolve the gyroscope, so revolve 1 he will t 1 it. b. *John wants to get under the bed, so under 1 he will get t 1 the bed. c. *John wants to be a neurolinguist, so neuro 1 he will be a t 1 -linguist. Although they are not fragmentary responses themselves, German modal particles (MPs) can accompany fragments, as Ott & Struckmeier (2018) show (79) To account for the observation that the fragment in (76) is interpreted in its base-generated position, and to account for the observation that immovable items often make for acceptable fragments, Weir (2014: 178-199) suggests that fragments undergo an exceptional application of movement that occurs at the PF branch of grammar. According to him, this accounts for why the fragment in (76) is interpreted in its base-generated position (the movement operation happens after transfer to the LF branch of grammar). One presumes that exceptional PF-movement can also be invoked to explain why the fragments in (79) 20 I can confirm that, at least for the small groups of native speakers I have consulted, the judgements provided for the English data in (77) hold for their Dutch and German equivalents. Future research must decide whether or not these fragmentary responses are considered acceptable in additional languages. 21 The fact that prepositions make for suitable fragments was noted early on (Zwicky 1982 are licit and for why the otherwise immovable elements in (77) can also purportedly move to escape clausal ellipsis in (78). Because the exceptional movement that purportedly derives fragments is only triggered when clausal ellipsis occurs, appealing to it renders this aspect of the M&D analysis unfalsifiable, which is problematic for any scientific theory (Popper 1963). This problem becomes more acute when one considers that, in languages that do not permit focusfronting in non-elliptical environments (such as English, which forbids presentational or contrastive foci from undergoing A-movement in question-and-response dialogues), all non-wh fragments must be formed via exceptional movement. The problem is further compounded by the fact that more than one type of exceptional movement is required under the M&D approach, as not all exceptional fragments (i.e. remnants of ellipsis that occupy a structural position they usually cannot) can be derived by PF-movement. For example, Abels & Dayal (2017), who adopt the M&D approach, argue that the derivation of multiple sluices in a number of languages involves an application of movement which, while usually covert (and hence applied in the interpretative component of the grammar), becomes exceptionally overt in clausal ellipsis environments. This movement, which therefore must occur in the narrow syntax to have both an interpretative and phonological effect, allows the second wh-phrase in a multiple sluice to escape ellipsis (81).

(81)
Everyone made a gift from something. But who 1 [ from what] 2 t 1 made a gift t 2 ?
To summarise: Problematically for the M&D approach, many fragments do not behave like A-moved phrases (e.g. with respect to scope-fixing) and many unmovable phrases make for suitable fragments. These problems are circumvented in the M&D framework by stipulating that ellipsis permits exceptional movement, but at the cost of creating an unfalsifiable theory.

The in-situ alternative
From an "in-situ" perspective, the observation that some fragments do not behave like A-moved phrases (see (76)) is unsurprising, as such fragments do not undergo A-movement when clausal ellipsis applies. Similarly, the observation that phrases that introduce nonat-issue content can accompany fragments (see (79)) is expected if the phonological operation that yields clausal ellipsis is correctly specified to avoid deleting (or suppressing Vocabularly Insertion inside) such phrases, as the PF-rule of clausal ellipsis in (48) already is.
Consequently, an advocate of the in-situ approach need not appeal to exceptional movement to explain why the fragments in (76) and (79) are acceptable and are interpreted in the manner that they are. An explanation that does not appeal to exceptional movement is also available for why the fragments in (78) are acceptable, too. The remainder of this subsection is dedicated to presenting this explanation.
To explain why the fragments in (78) are acceptable, we must look to their antecedent clauses, which are all alternative questions. With regards to their impact on the discourse, standard alternative questions simultaneously (i) inform an interlocutor of what all of the salient propositional alternatives in the context of utterance are and (ii) ask her to choose between them. This exhaustive property of alternative questions prevents any implicit wh-question from being invoked from them (Biezma & Rawlins 2012: 387). Importantly for the current study, this entails that explicit alternative questions can themselves be maximally-prominent in the QUD and can therefore serve to semantically license clausal ellipsis.
The technical details of how alternative questions semantically license clausal ellipsis proceed as follows. In the Structured Meaning framework, alternative questions can be represented as a focus-background structure with a choice function as the focus and a λ-abstraction over the choice function as the background. The choice function in the focus position of the focus-background structure is restricted to the set of alternatives listed in the alternative question (Krifka 2001). As in §3.2, I assume that the creation of this semantic structure is triggered by Force Q . Alternative questions also exhibit Foc, which enters into a syntactic Agree relation with the head of an fP that adjoins to the coordinated focused phrases (this fP is therefore not subject to the fP-intervention condition, see footnote 13). 22 This is therefore the main difference between alternative questions and wh-questions, as wh-questions exhibit a "CP and fP" pairing instead of the "Foc and fP" pairing exhibited by alternative questions (see the syntax trees in (38) and (40) for the syntax of wh-questions). An alternative question such as (78aA) therefore has the syntax in (82)  According to Background-matching condition presented in (32), clausal ellipsis is licensed in a response to the alternative question in (82) if its background matches the background in (83). This situation obtains in (78aB), as the focus-background structure for its underlying clause in (84)  Importantly, the acceptability of the fragmentary response in (78a) (and indeed, the acceptability of each of the fragments in (78)) is determined by its licensing question. If its licensing question does not involve standard A-movement, as is the case for alternative questions in English, then the fragment is judged to be acceptable. Conversely, if its licensing question does involve standard A-movement, as with wh-questions in English, then the fragment should be judged as unacceptable. This is because none of the focused phrases in the licensing questions in (78) can undergo wh-movement in English when replaced by wh-phrases to form standard, non-echoic questions. Consequently, the current theory predicts that assertions that display the same focused phrases as the questions in (78)  We have now arrived at an explanation for why the fragments in (78) are acceptable: they are acceptable because clausal ellipsis can be recovered from their antecedents, which are an explicit alternative questions. Unlike an explanation couched in the M&D framework, this explanation makes no recourse to exceptional movement, and is also able to account for why such fragments are licit as responses to explicit alternative questions but are illicit as responses to implicit wh-questions.
To summarise: Because remnants of clausal ellipsis need not undergo A-movement in the in-situ framework, this approach is able to provide a natural explanation for why certain fragments do not behave like A-moved items. It is also able to account for why items that cannot undergo A-movement in non-elliptical environments make for licit fragments without appealing to the notion of exceptional movement (unlike the M&D approach). The particular version of the in-situ approach advocated in this paper can also explain why immovable items are only judged as acceptable in particular discursive contexts in English (e.g. when anteceded by an explicit alternative question); a subtle distinction which cannot be made within the M&D framework.

Wh-in-situ languages
The remit of the Island-Sensitivity Generalisation in (7) is purposefully restricted to languages with wh-movement. This is because having an island-bound correlate typically has no effect on the acceptability of fragments in wh-in-situ languages such as Japanese be more straightforwardly specified for (iv), in which it coordinates propositions, than for (83) (Abe 2015 and references in there), Korean (Kim & Park 2016: 27-28), and Turkish (İnce 2012), even when no island-evading anisomorphic source is available. This is exemplified by the non-wh presentationally and contrastively focused fragments in (86B) and (87B), which come from Turkish (İnce 2012: 206 When one considers that no predicational copular clausal short source is available for the fragments in (86) and (87) (as the ungrammaticality of (88) shows), one must conclude that Turkish fragments are genuinely island-insensitive. To account for these data within the M&D framework, İnce (2012) adopts Merchant's (2004) idea that island-sensitivity is a phonological phenomenon, which is obviated when the lower links in an A-chain that crosses an island boundary are fully contained in a phrase that undergoes ellipsis (see Merchant 2004: 705-709 for details). Aside from being an unfalsifiable theory, İnce's analysis fails to explain why some fragments are indeed island-sensitive in Turkish:
yes out.of.obligation Let us now consider these Turkish data from an in-situ perspective, abstracting momentarily away from the technicalities of the particular in-situ analysis adopted in this paper but upholding the QUD-syntax Correspondence conjecture. When viewed from this perspective, the data receive a natural explanation. Because Turkish is a wh-in-situ language, the QUD that licenses (86B) and (87B) is syntactically derivable (see (90)) and therefore available for licensing fragments when invoked from assertions. Although having islandbound wh-phrases is usually no obstacle to forming questions in wh-in-situ languages such To satisfy the Background-matching condition and therefore license clausal ellipsis, fP must also be base-generated as an adjunct to a corresponding island in any candidate elliptical response to (92). Because deletion avoids the syntactic sister of f, this gives rise to the prediction that a fragmentary response to a question such as (92), in which the whphrase is contained in an island, must itself be island-sized (and no smaller). Problematically, this prediction is incorrect. As the Japanese example in (95) shows, and as the Turkish examples in (86) and (87) have already shown, fragmentary responses to questions in which the wh-phrase is contained in an island can correspond to the whphrase itself, rather than to the island that contains it. professor-nom what-acc lecture scene-acc rokuon-sita no? tape-recorded Q 'What thing was it that Hanako tape-recorded a scene of the professor lecturing that thing?' B: Gengogaku-o desu.
linguistics-acc be 'It's linguistics.' Although Abe (2015) has convincingly shown that fragments such as (95B) cannot be derived from island-evading anisomorphic sources (contra Saito 2004), one could still contend that, because the Japanese fragment in (95B) is a cleft-like structure, the clausal ellipsis that derives (95B) is governed by a different licensing constraint to the Background-matching condition.
Rather than dismiss fragments in wh-in-situ languages such as Japanese as somehow ontologically different from fragments in wh-movement languages, my current solution to the problem posed by (95B) for the current analyis (which is perhaps not the ultimate solution) is to posit an additional yet silent f-particle within wh-questions in such languages; one which does not enter into an Agree relation with a clause-peripheral head.
for languages in which wh-phrases are focused in standard single-wh constituent questions (i.e. wh-in-situ languages such as Japanese; see Truckenbrodt 2013). It cannot be extended to wh-movement languages such as English or German, as A-moved wh-phrases in wh-movement languages are inherently unfocusable in standard, single-wh constituent questions (ibid.). See Reich (2002: Footnote 21) for a similar analysis.

Summary of §5
I have shown in this section that, in addition to successfully deriving the Island-Sensitivity and Preposition-Stranding Generalisations from §2, the in-situ approach to clausal ellipsis defended in this paper makes correct predictions about certain types of fragments that can only be explained in the M&D framework by recourse to ellipsis repair. These include fragments that do not exhibit A-movement properties in English, and fragments in wh-insitu languages.

Conclusion
In this paper, I presented an in-situ analysis to clausal ellipsis based upon the Q-based approach to questions and foci consolidated in and popularised by Cable (2010). This insitu analysis, which is a minor variant on Merchant's (2004) influential theory of clausal ellipsis, allows remnants of clausal ellipsis to remain within an ellipsis site, with deletion taking place around them.
I argued that recent advances made by Weir (2017) in the study of how the meaning of clausal ellipsis is recovered lead quite naturally to the conclusion that the meaning of a clausal ellipsis site is always recovered from a syntactically generated question, regardless of whether this question is explicitly uttered or merely implied. This conclusion was epitomised in the QUD-syntax Correspondence conjecture. I demonstrated that, once this conjecture is adopted, two properties displayed by fragmentary responses that are hallmarks of A-movement (namely, their sensitivity to syntactic islands and their systematic (in)ability to appear as "bare" DP fragments that are interpreted as complements of prepositions) are straightforwardly explained without appealing to the idea that remnants of ellipsis themselves necessarily undergo A-movement. In other words, I demonstrated that the Island-Sensitivity and Preposition-Stranding Generalisations can be derived without recourse to syntactic movement of the remnant of ellipsis. I also demonstrated that the in-situ approach to clausal ellipsis correctly captures the (un)acceptability of immovable fragments in English and all fragments in wh-in-situ languages such as Turkish and Japanese without appealing to the untestable notion of ellipsis repair.
As mentioned in the main body of the paper, the arguments I presented do not automatically invalidate analyses of clausal ellipsis that require remnants to undergo A-movement out of the ellipsis site. Instead, these arguments serve to emphasise the viability of in-situ approaches to clausal ellipsis, and also provide hints that in-situ analyses of ellipsis may turn out to be superior to their movement-based counterparts.