The grammaticalisation of a copula in vernacular Arabic

It is standardly assumed that Arabic copula constructions with present tense interpretation involve either a null copula or a pronominal copula. This paper provides evidence that some Arabic vernaculars are developing a three-way split, with an additional copula form occurring in some predicational copula clauses. This form has grammaticalised out of the active participle form of the posture verb meaning ‘sit’. While at different stages of development in different varieties of Arabic, this emergent copula shows the characteristics of a locative (temporary and/or permanent, depending on the variety) or contingent state (stage-level) copula, standing in contrast with the use of a null copula strategy, which marks characterising/defining individual-level properties. We propose a grammaticalisation trajectory for this copula in the Arabic varieties based on the comparative patterns of variation across those dialects, showing that the trajectory postulated for other, typologically distinct languages is also applicable to Arabic and hence providing further support for it. We suggest that there is also evidence of a distinct but related trajectory in some varieties which have developed a semantically bleached lexical existential predicate from this same form. We provide further evidence of the importance of the temporary/permanent split in the copula systems of Arabic arguing that the developing split copula system based on the active participle of the ‘sit’ verb is in alignment with the development of two other parallel split copula systems in other geographically diverse Arabic varieties, which use different bases/strategies for grammaticalisation.


Introduction
Arabic is generally described as a language in which present tense copula clauses exhibit a null (or zero) copula in predicational copula constructions and a pronominal copula in identity or equative copula clauses. This paper argues that this picture is too simple for a number of dialects and overlooks some of the empirical data. We focus on this data, and provide a more comprehensive picture of the real state of affairs as it is developing, synchronically, where in at least some Arabic dialects, an additional overt copula is emerging in the present tense non-verbal predicational constructions. As a result, these dialects display a three-way split, synchronically, in copula constructions with present tense interpretations. We will show that the niche that this copula has carved out for itself resembles the distribution of the contingent or locational copula familiar from other languages which exhibit a two-way split in their predicational copula constructions, and hence providing further support for the significance of this dimension from an additional language family. We will focus in some detail on the distribution of this copula form addressing the questions (i) which varieties do we find it in, and how does this correlate with the lexical use of this same item, (ii) what other properties might be relevant, and (iii) how we might account for this grammaticalisation path? We provide a trajectory of change leading to the copula function, and since the emerging specialised copula strategy that we discuss involves grammaticalisation from a posture predicate, we will consider how the grammaticalisation trajectory for Arabic, might be related to the grammaticalisation paths trodden by such parallel specialised copula functions derived from posture verb sources and discussed in the literature for other, typologically distinct language families. We also argue that a further lexical/semantic development has also taken place in some dialects, from the same source, and propose a trajectory of change for this distinct but related development. Neither of these particular grammaticalisation path has, to our knowledge, been discussed previously for Semitic.
In support of our main hypothesis concerning the emergence of a specialised contingent copula, we bring together two other parallel but independently-emerging three-way split copula systems in other Arabic varieties, suggesting that these three different developments appear to be moving in the same direction, in that they all represent the morphosyntactic realisation of a similar semantic distinction within the copula system. In each case the emerging form is also additionally the form that is found widely in contemporary dialects as an aspectual auxiliary with a core meaning of progressivity. This in itself raises questions concerning the relationship between these two grammaticalised forms, which are not always necessarily identical, and do not have precisely the same dialectal range. We do not address these additional questions here, but focus more narrowly on demonstrating the existence of this emergent copula and formulating a grammaticalisation trajectory for the pattern of copula usage we demonstrate; a necessary precondition for addressing these further theoretically important issues.

Copulas and copula constructions
Since the focus of this paper is on copula constructions, we start by providing some sense of how we understand this term. We use the term to refer to the basic construction or constructions used to encode the identity of two participants and to express group membership, classification, location and the ascription of a range of properties to a participant, excluding verbs like become, remain, seem, feel, which are sometimes referred to as semicopulas. In section 2.1 we provide some background on the expression of non-verbal predication crosslinguistically and section 2.2 briefly reviews some salient facts concerning non-verbal predication and split copula systems, focussing mainly on Spanish and Irish.

The expression of non-verbal predication
Following Higgins (1979)'s classic study and subsequent literature (e.g. Mikkelson 2011; Roy 2013) we can distinguish three major types of copular constructions, according to whether or not the subject and the "complement" XP of the copula are referential, as shown in Table 1 (adapted from Mikkelson 2011from Mikkelson : 1810 and (1).
(1) a. The room is untidy. predicational b. Cicero is Tully. equative c. The only person I know is Kim. specificational The primary focus here is on the predicational sub-type of copula constructions. 1 We take the predicational copula construction to be a sentence type in which the lexical or contentful predicate is some non-verbal element (Mikkelson 2011(Mikkelson : 1805. The English examples in (2) are predicational copula constructions in which the sentential predicate is respectively adjectival, nominal and prepositional. In such clauses, the forms of be are copula verbs, that is, linguistic elements which appear in some sort of mediating or linking role between subject and predicate in predicational sentences in which the main semantic predicator is a non-verbal element. Hence we use the term predicational copula construction to include both property ascriptive examples, as in (2a) and (2b), and locational clauses, as in (2c).
(2) a. John is very ill. b. Jane was a teacher. c. The children are in the garden.
It is often stated that in copula constructions the copula element is totally devoid of meaning, at least in predicative copula constructions (Hengeveld 1992: 32;Pustet 2003: 5), and, in some accounts, also in equative and specificational constructions (Partee 1987). We assume that the predicational copula has no inherent lexical semantic content but simply plays a role in semantic composition, i.e. in applying the predicate to the argument (Partee 1987;Roy 2013) and in carrying tense information, although such matters are orthogonal to our concerns here. 2 In languages with multiple copulas, a choice between competing forms generally corresponds to some semantic property, and hence may be thought to realize the competing values of that property, or is to constrain any such property to be present, depending on the precise details of the approach adopted. Crosslinguistically we find a great diversity in the syntax of copula constructions. Languages differ in terms of the diachronic source and synchronic syntactic status of copula or linking elements; copulas may be full words or affixes, and common sources include pronouns, deictic particles and verbs (Devitt 1990;Pustet 2003). They also differ as to whether, and under what conditions, they require a copula clause to contain an overt copula or linking element. For example, no overt copula is required in predicational copula constructions with a present tense interpretation in Russian.
(3) a. Russian (Roy 2013: 119) Segodnja reka spokojna. today river calm.sform 'Today the river is calm.' b. Russian (Roy 2013: 119) Ivan byl goloden. Ivan was hungry.sform 'Ivan was hungry.' Arabic also exhibits this tense-conditioned morphosyntactic alternation between the absence and presence of a copula element in predicative copula constructions. We will 2 See also Rothstein (1999) for the opposing view that the copula element does make a semantic contribution in predicational copula constructions.

NP1 copula XP
predicational referential non-referential equative referential referential specificational non-referential referential use the term null copula to refer to copula-free copula constructions, without commitment to any particular syntactic analysis. When a language has multiple copulas, a range of different factors may govern the choice of copula. Choice of copula can be determined by various clausal features such as tense and aspect or polarity, but also by the morphosyntactic category of the predicate phrase itself, as in Bambara (Niger-Congo) which exhibits a four-way choice between copula forms, dependent on the category of the predicate (Pustet 2003: 46). Equally, it may be determined by the distinction between locational and non-locational clauses, as in Kinyarwanda (Bantu) (Jerro 2015) or by other semantic or pragmatic characteristics of the predicate, clause or subject argument (see Pustet 2003: 45-53). For example, Kuuk Thaayore (Paman) (Gaby 2006: 460-477) has five verbs used as optional copula verbs (nhiin 'sit', than 'stand', wun 'lie', yan 'go' and yoongke 'hang'). The default choice of copula in ascriptive and locative copula clauses for higher animates is yan 'go', with the use of a different copula introducing additional connotations, which may or may not relate to the postural sense itself. The choice of an optional copula for animate subjects in ascriptive copula clauses is determined by the canonical posture of the animate entities in question.

Split copula systems
Split copula systems implicating a semantic/pragmatic distinction between permanent or inherent properties and temporary, contingent or temporally-bounded properties are quite widely attested. Stassen (1996) notes that an alternation between a null and a locational copula encoding for nominal predicates occurs in several Carib languages (Apalai, Hixkaryana, Macushi) and the Dravidian languages Tamil, Telugu and Kannada. The locational encoding for predicate nominals is associated with non-habitual, contingent or temporary states. As is well known, Irish makes use of forms of two distinct verbs in copula constructions, the copula verb is and the so-called substantive verb bí (Stenson 1981;Carnie 1995;Doherty 1996). Prepositional and adjectival predicates, whether interpreted as permanent, inherent properties, or as temporary states, properties or locations appear with bí (glossed simply as bi) in copula constructions. In the modern language, the copula use of is with adjectival and prepositional predicates is highly circumscribed and a vestige of Old Irish (Doherty 1996: 36-7;Stenson 1981: 99).

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Irish (Doherty 1996: 2) Is dochtúir é. cop doctor 3sgm.acc 'He is a doctor.' Irish (Doherty 1996: 27) Is é Seán an dochtúir. cop 3sgm.acc Seán the doctor 'Seán is the doctor.' What is of interest is that a clear contrast arises between a nominal copula construction with is (5)-(6) and one in which the nominal predicate is introduced by the preposition ar 'in' (4a), where the substantive verb bí is used. Several different characterisations of the associated semantic distinction are suggested in the literature; Stenson (1981: 94-5) takes nominal copula constructions with is to be defining or characteristic, and those with bí to be suggestive of the attainment of a state, and which is more anchored in time. Carnie (1995) and Doherty (1996) relate the contrast to the distinction between individual-level and stage-level predicates. Roy (2013) characterises the semantic distinction differently, suggesting that is is limited to maximal predicates, that is, predicates devoid of "perceptible spatio-temporal subpart properties" (Roy 2013: 90), while bí occurs with situation-descriptive predicates which are dense, that is, which hold continuously for every sub-interval of the eventuality, and habitual or generic sentences. 4 Consistent with these various characterisations of the difference, the nominal copula construction with is in the past tense shows lifetime effects, such that (7a) entails that Seán is dead, while the prepositional nominal construction with bí does not (7b). The distribution of ser/estar as copula forms in predicative constructions in Spanish is also sometimes characterised in terms of the distinction between individual-level and stagelevel predication. 5 Maienborn (2005a) offers a discourse-based account of the distinction within DRT, Luján (1981) (inter alia) takes an aspectual view associating estar with the feature [+perfective], and Roy (2013) proposes that copula estar occurs with dense predicates while predicative copula ser marks maximal predicates and those which are non-dense, that is, have spatio-temporal subpart properties and are not required to hold continuously for every sub-interval of the eventuality. A good overview of the facts for Spanish and the issues and challenges faced by different theoretical accounts is provided in Camacho (2012). Predicative NPs occur only with ser, unless preceded by the prepositional marker de, in which case they occur with estar, and receive a particular, transient, interpretation, as in the contrast in (8).
(8) a. Spanish (Camacho 2012: 455) Obama es/*está (el) presidente desde el 2009. Obama is(ser)/is(estar) (def) president since def 2009 'Obama has been (the) president since 2009.' b. Spanish (Camacho 2012: 455) Obama está/*es de presidente desde el 2009. Obama is(estar)/is(ser) of president since def 2009 'Obama has been in the role of/acting as president since 2009.' Many adjectives will occur felicitiously with both ser and estar in predicative copula constructions-in the former case a permanent, inherent or intrinsic property is ascribed to the subject, while in the latter case, the property might be temporary, contingent or situation-descriptive. Such a contrast is provided in (9). Similarly, the absolute/transient distinction also applies with PP predicates, in general. With locational PPs, if the subject is a movable entity, in which case the location may be temporary, locative prepositions occur with estar, as in (10).

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Spanish (Camacho 2012: 453) Alejandro es agradable / está agradable. Alejandro is(ser) pleasant / is(estar) pleasant 'Alejandro is pleasant/is being pleasant (today).' (10) a. Spanish (Camacho 2012: 456) Los libr-os están/*son en el estante. def.plm book-plm are(estar)/*are(ser) on def shelf 'The books are on the shelf.' b. Spanish (Camacho 2012: 456) Mi hermano está/*es en Buenos Aires. my brother is(estar)/*is(ser) in Buenos Aires 'My brother is in Buenos Aires.' This section has provided background to contextualise our discussion of Arabic predicative copula systems in subsequent sections. We have observed that many copula systems display a split which is grounded in a distiction between permanent, inherent or immutable properties and those which are temporary, contingent or episodic. In the following sections we first outline the picture for Arabic dialects as generally described. We see that two conditioning factors are standardly thought to be relevant to this split copula system-the clausal feature of tense and the distinction between predicative and non-predicative clause types. We then turn to Maltese, where the distribution of copula forms is more complicated, being sensitive to additional conditioning factors, including copula construction type (i.e. predicative versus non-predicative; locational versus non-locational), the clausal feature of tense, and the distinction between enduring and temporary properties.

Arabic copula constructions
The theoretical and descriptive literature on Arabic generally takes the basic facts for copula clauses to be as follows. Copula constructions of all types which are temporally situated in the non-present are mediated by the presence of a copula form, most generally a form of the verb kān(a) 'be.pfv.3sgm'. With present time reference, affirmative non-verbal predications (PPs, APs and indefinite NPs) are not mediated by the presence of an overt copula element. In equative (i.e. identity and identificational) clauses with present time reference we find forms identical to the 3rd person strong pronouns, which are often referred to as pronominal copulas in this context. We shall have nothing more to say about equatives, which have referential complements, in this paper, restricting our focus to predicational structures. (11) and (12) illustrate the basic distribution of the null (or zero) copula and the so-called pronominal copula, showing that the pronominal copula is ungrammatical in predicational copula constructions with PP, AP and indefinite NP predicates, while the null copula is ungrammatical, or at least marginal, in equative copula constructions. It is this contrast which is the essential focus of theoretical analyses of Arabic copula constructions, whether in Modern Standard Arabic or the spoken dialects. There is a relatively large, mainly theoretically oriented, literature on copula constructions in Arabic, with considerable attention being given to the status and analysis of the so-called pronominal copula, including Eid (1983), Doron (1986), Eid (1991), Benmamoun (2000), Aoun et al. (2010: 35-44), Choueiri (2016), and Alharbi (2017) among many others. Distinctions among predicational copula constructions are not addressed, or generally acknowledged, despite the occurrence of relevant examples in descriptive sources. As the examples in (11b) and (12b) illustrate, there is no distinction between predicational and equational clauses in the past tense, where the fully inflected perfective form of the verb kān 'be' is employed, and the same is true for the clauses in the future, with the future-marked imperfective form. 6 (11) a. Lebanese Arabic (Choueiri 2016 (Choueiri 2016: 102) l-bornayṭa kēn-it meškle/ħəlw-e/b-l-bēt def-hat.sgf be.pfv-3sgf problem.sgf/nice-sgf/in-def-house 'The hat was a problem/nice/at home.' For completeness, the example in (13) illustrates a further point, namely that the pronominal copula may additionally occur in predicational copula clauses with definite NP predicates. 7

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Lebanese Arabic (Choueiri 2016: 102) hayde ∅/kēn-it/hiyye Amal Alamuddin dem.sgf ∅/be.pfv-sgf/cop.3sgf Amal Alamuddin 'This is/was Amal Alamuddin.' Despite these further wrinkles, and the existence of further differences and variation across the range of Arabic varieties, the basic generalisation which is relevant here is that the pronominal copula is limited to definite NP "complements" and the null copula, that is, the absence of a copula, characterises present tense affirmative predicational sentences with AP, PP and indefinite NP predicates. Three main dimensions are thus relevant to the distribution of forms in copula constructions: predicational vs non-predicational, definite vs indefinite, present vs non-present. The overall picture for the Lebanese Arabic data which emerges from Choueiri (2016) is the distribution of forms shown in Table 2. Similar distributions are described elsewhere for other varieties. 8 It is this (idealised) picture which is addressed in various ways in theoretical work on Arabic copula clauses and which we challenge in this paper, arguing for the recognition of a further split in the predicational copula system itself.

Maltese: A recognised multiple copula system
As a first step in establishing our central point, which is the existence of an overt predicational copula in Arabic with present tense interpretation, we discuss the relatively well-documented facts of Maltese, a Maghrebi/Siculo-Arabic dialect of Arabic (Brincat 2011). In Maltese, the existence of multiple copulas for non-verbal predication is both relatively well described and rather stable and categorical in its distribution.
The distribution of forms in copula constructions is sensitive to a number of factors; Maltese verbless sentences and copulas are discussed in Borg (1987;1988), and Stassen (1996), and more recently in theoretical work by Dalmi (2015;. 9 8 Although it is not given much attention in the literature (for example, it is not mentioned in Choueiri 2016), the distribution of the negative pronominal copula across the vernaculars is quite different from that of the affirmative pronominal copula, with potential consequences for the validity of theoretical analyses of the latter. The negative pronominal copula is not excluded from indefinite predications. Furthermore, while the pronominal copula of affirmative clauses is restricted to 3rd person forms, this is not true of the negative pronominal copula which, in most dialects, has a full array of inflected forms, allowing the subject to be dropped, as well as a default agreement form. By contrast, in Sason Arabic (an Anatolian variety), negated (pronominal) copulas are restricted to 3rd person forms, but in the singular show a gender distinction that is in turn not realised in the affirmative paradigm (see Akkuş & Benmamoun 2016: 166). All in all, a simple extension of the analysis proposed for the affirmative pronominal copula to the negative pronominal copula cannot be assumed. Moreover, the distribution of the affirmative pronominal copula in non-declarative clauses is not precisely the same as that in declarative clauses, being readily available in places where it wouldn't have figured in declarative contexts such as the ones illustrated above. 9 Dalmi's perspective is theoretical rather than empirical; she discusses examples from the other sources cited in making a theoretical proposal for the treatment of the stage-level/individual-level distinction in terms of the alternative state model (Maienborn 2005a;b;. Descriptively, Dalmi has mischaracterised somewhat the actual facts, especially when it comes to locative structures. For this reason we stick with examples taken from the source, which is Stassen (1996). As well as the 'be' verb, the null copula, and the pronominal copula, which is restricted to 3rd person forms in the affirmative, and displays the full array of paradigmatic forms in negative contexts, two additional elements are found in copula constructions in Maltese: the sgm form qiegħed, along with the corresponding sgf and pl forms, and jinsab '3m-passfind.ipfv.sg', along with the rest of the inflected imperfective forms of this stem. Since our focus here is on the factors governing the distribution of qiegħed, we omit jinsab from further discussion, noting only that it may occur in some types of adjectival and locational predications. Qiegħed and its inflectional counterparts are etymologically the active participle forms of the lexical verb meaning 'sit', but neither the active participle, nor the verb itself (except in lexicalised phrases where the verb is in contrast with the verb 'stand; arise') occur with this lexical meaning any longer, and hence we gloss these forms here as be+inflection.
In Maltese, as in other Arabic varieties, the distribution of the verb kien 'be.pfv.3sgm' in copula structures is determined by the intended temporal reference, with forms of kien occurring only in non-present tense copula clauses with all predicate types (nominal, adjectival and locational).
(16) a. Maltese (Stassen 1996: 279) Ġanni l-ħabs. Ġanni def-prison 'John is in prison.' b. Maltese (Stassen 1996: 279) Il-vapur qiegħed il-port. def-ship.sgm be.sgm def-port 'The ship is in the harbour.' c. Maltese (Stassen 1996: 279) It-tifel j-i-n-sab id-dar. def-boy.sgm 3m-epent.vwl-pass-find.ipfv.sg def-house 'The boy is at home.' The use of a bare locational NP, that is, one without a locational preposition, as in the examples in (16), is subject to various semantic constraints involving animacy and stereotypicality/habituality, which do not concern us here. For example, Stassen (1996) suggests that the use of the bare locational NP is infelicitous when the locations are not habitual, characteristic or stereotypical, and hence, the examples in (17) are odd. Locational predications may also be expressed by means of a PP, as in (18). (17) a. Maltese (Stassen 1996: 281) ?L-istudent il-ħanut. def-student.sgm def-shop 'The student is in the shop.' b. Maltese (Stassen 1996: 281) ?Il-qassis il-ġnien. def-priest def-garden 'The priest is in the garden.' (18) Maltese (Stassen 1996: 281) Iċ-ċacetta ∅/qiegħd-a fil-kexxun. def-key.sgf ∅/be-sgf in.def-drawer 'The key is in the drawer.' The following examples show that both the inflected sgf qiegħda and the zero copula occur in locational predications, irrespective of whether they are temporary or permanent; (19a) is clearly a permanent location, while (19b) describes a temporary state of affairs. This in turn is in contrast with the distribution of the pronominal copula, illustrated below through the 3sgf pronominal copula form hija, which is ungrammatical in locative contexts.
Beyond locational predications, qiegħed may also occur with nominal and adjectival predicates, but here the use of this strategy, as opposed to the neutral, zero copula strategy, is associated with a semantic distinction, and produces a clear interpretive effect (Stassen 1996: 277). Three strategies are available for nominal copula constructions: the pronominal copula, the zero copula and qiegħed. The pronominal strategy occurs in certain types of nominal copula clauses, most typically those involving identity and identification, including the specification of a hyponymic relationship, and generic statements. (20) provides an example.

(20)
Maltese (Stassen 1996: 289) Il-ġiżimina ∅/hi(ja) fjura. def-jasmine.sgf ∅/cop.3sgf flower.sgf 'Jasmines are flowers.' The factor which is relevant to the choice between the null copula and the locational copula qiegħed can be characterised as time stability or permanency (Stassen 1996). The use of qiegħed is associated with states of affairs which are temporary, contingent or accidental, rather than permanent, inherent or characteristic. Whether this is possible will therefore depend on whether the property or class membership is amenable to such interpretations ("acceptability crucially depends on the degree to which speakers are prepared to view a class membership predicate … as temporary " Stassen 1996: 286). (21a) is acceptable because being the examiner can be viewed as a temporary class membership, while (21b) is unacceptable because this concerns a permanent class membership. A similar interpretative effect is found with the use of the contingent or tem-porally-anchored copula qiegħed/qed in (22)  As for clauses with adjectival predicates, the null strategy is available across the board, but the distribution of both qiegħed and the pronominal copula with this class of predicates is associated with the distinction between the ascription of contingent and permanent properties, with the consequence that these two strategies are not uniformly available with all predicative adjectives. In (23), the pronominal and zero copulas give a time stable interpretation, while qiegħed gives a temporary/contingent interpretation, corresponding to the distinction between inherently quiet by nature, and being quiet, or behaving in a quiet manner. In (24), on the other hand, the contingent qiegħed is impossible, because shortness cannot be construed as a temporary property in this case. 11 (23) Maltese (Stassen 1996: 292) It-tifel ∅/hu(wa)/qiegħed kwiet. def-boy ∅/cop.3sgm/be.sgm quiet.sgm 'The boy is quiet/being quiet.' Maltese (Stassen 1996: 295) L-arblu ∅/hu(wa)/*qiegħed qasir. def-pole.sgm ∅/cop.3sgm/be.sgm short.sgm 'The pole is short.' The basic distribution can be summarised as follows. The alternation between the zero copula and the marked copula qiegħed is essentially not meaningful with locational predicates, while the pronominal copula is excluded from such constructions. In nominal copula clauses, the pronominal copula occurs in a particular semantic range of constructions, most centrally identity and identificational cases, 12 and the use of qiegħed, instead of the zero copula, is associated with impermanency and the ascription of temporary class membership. The use of qiegħed is also associated with temporary or contingent properties in adjectival predication, and is excluded when such interpretations are impossible, while the pronominal copula is associated with time-stable interpretations with these predicates. The use of this strategy, which is itself an innovation when compared to other Arabic vernaculars, gives rise to contrasts of the type in (23), where the choice of the pronoun versus qiegħed expresses what Stassen (1996: 292) calls the permanency parameter. These distributional regularities, which are exemplified above for declarative clauses, hold equally well for other clause types such as exclamatives and interrogatives.

Arabic varieties beyond Maltese
We have seen that in addition to be, and the zero copula/pronominal copula split, Maltese has a further form, qiegħed/qed, etymologically the act.ptcp of the lexical root corresponding to the posture verb 'sit' of other Arabic varieties. This form is in free variation with the zero copula in the expression of locational predications. With adjectival and nominal predicates, however, the use of qiegħed/qed imparts a particular semantics. In Maltese, these act.ptcp forms no longer have any lexical meaning as posture verbs. Alongside grammaticalisation as a copula, we also find in Maltese the grammaticalisation of the same inflectional form as a progressive auxiliary (Borg 1987;1988;Agius & Harrak 1987). In this section we show that the cognate items, which are grammaticalised forms of the act.ptcp of the root 'sit', actually also occur in usages which might be considered to be copula, in other Arabic varieties. Our claim is that a posture-verb-derived copula is in fact much more widespread across the Arabic dialects, and that in all of these varieties, as in Maltese, the grammaticalisation of the same set of forms as aspectual auxiliaries is equally present. Many of the examples we will discuss are drawn from descriptive sources which do not discuss them in the context of copula constructions, and indeed rarely characterise them as involving copulas. Hence, the wider theoretical claims and implications for grammaticalisation put forward here, are here our own alone, and are not drawn from those sources.

Libyan
Consider now these examples from Libyan, which involve a verbal element which is the act.ptcp form of what is etymologically the root 'sit', but which synchronically is the verb meaning 'stay; remain'. In Libyan, gāʕəd does not mean 'sitting' at all (Pereira 2008, as also reported in Rubin 2005). We have examples such as the following, where our glossing and translation are intended to maintain the insights from the original descriptive source, which in some cases is indicative of a degree of ambivalence about the analysis of these items. To this end, we have provided the original free translation in French alongside our own English rendering, and reflect the original French gloss restant as 'stay. act.ptcp', and se trouvant and étant as be, which is to be understood as indicative of a copula function in such contexts.
An example such as (25), glossed as 'stay.act.ptcp' (restant in the original), is perhaps suggestive of a lexical predicate gaʕad 'sit.pfv.3sgm' with the semantically bleached lexical meaning of 'stay; remain; continue to be (in a location)', combining with a locational modifier to give a meaning of continue to be in a location. If we associate the continue to be sense with gāʕəd in (25), then this might suggest (taking a conservative view) that we are dealing with some bleached lexical function of the participle form in this variety, rather than a use that necessarily has a copula function. In isolation, then, (25) is consistent with a view of gaʕad as a bleached lexical predicate with the meaning shown in small capitals in (26), where the location phrase is a selected dependent or a modifier.

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Libyan Arabic (Pereira 2008 Examples such as (34) present their own puzzle, the issue being whether what we see here is a copula use extending beyond locational predication to use in the ascription of contingent or temporary properties, or whether what we see here is the figurative extension of a stative predicate stay, remain beyond the locational domain, just as in English John remained/stayed silent throughout this diatribe. Clearly, distinguishing between these is a more than delicate matter, but we note that (34) is glossed and translated as a copula construction by Pereira (2008 Other examples are more questionable. In (35) Pereira in fact glosses the act.ptcp form gāʕəd as an adverbial 'still' (toujours), which might suggest that it is only a continuative aspectual value which is maintained. 15 This is however still consistent with viewing it as a temporally-anchored copula.

(35)
Libyan Arabic (Pereira 2008: 417) ɛlē-ma ṣəllħ-u fi-h gāʕəd as much as repair.pfv.3-pl in-3sgm.gen be.act.ptcp.sgm šəkl-a zēy əz-zəbb! appearance.sgm-3sgm.gen like def-dick 'Ils ont beau le réparer, ça a toujours l'air d'être une grosse merde!' 'However much they repair it (i.e. no matter what they do to repair it), it still looks rubbish/crap!' Given this fact about Libyan, an anonymous reviewer rightly asks how we might resolve the question of whether gāʕəd in the examples above has a true copula function, or simply represents a figurative extension of stay/remain to mean something like is still? They observe that since expressions such as stay, remain and is still involve a presupposition that the state holds as a continuation of a previous state, and a simple copula such as is lacks this presupposition, we might use a context to test where such a presupposition is ruled out, to test whether gāʕəd is still felicitous. The examples in (36), suggested by the reviewer as counterparts to (30) and (34) respectively, are such contexts, and hence provide further evidence for the conclusion that we are indeed dealing with a copula function of gāʕəd.
(36) a. Libyan Arabic (pc, Aicha Saad) ʕədnān ʕamr-a mā sāfar, bas tawwa gāʕid Adnan life-3sgm.gen neg travel.pfv.3sgm but now be.act.ptcp.sgm bərra abroad 'Adnan has never travelled before, but now/at the moment he is abroad.' b. Libyan Arabic (pc, Aicha Saad) kin-t dīma na-xdim bas tawwa gāʕid blā be.pfv-1sg always 1-work.ipfv.sg but now be.act.ptcp.sgm without xidma work 'I used to always work, but I am now without work.' The conclusion that can be deduced from the above array of data and usages of gāʕəd is that there seems to be clear evidence for a locative copula use of this act.ptcp form in this variety, apart from broader semantic bleaching of the lexical posture predicate itself. Furthermore, in relation to the copula function, there may additionally be some evidence of extension beyond locative predicative constructions.

Chadian
Chadian Arabic (for which a major source is Abu Absi & Sinaud 1968, a pedagogical/descriptive manual) is another variety in which the act.ptcp form gāʕid does not mean 'sitting' at all, as is also the case with its verbal counterpart. Rather, it is used as a locational verb 'be present', i.e. 'is situated/is located/exists', as illustrated through (37) (Kontzi 1986: 23) ar-ruħ hana ar-rabb gāʕid fōg-i def-spirit.sgm of/gen.mrkr def-Lord be.act.ptcp.sgm on-1sg.gen 'The spirit of the Lord is upon me.' Luke, 4: 18 It is worth noting that the examples above are not simply semantically bleached lexical usages meaning 'stay' or 'remain'. Even though they are all locational clauses, they do not have the additional "continuative" nuances which would follow on that view. gāʕid is clearly an optional strategy with such locative PPs, occurring optionally with locational predicates of all sorts, in both declarative and interrogative clauses. As observed specifically for (41b) (Where are you? is surely asking about a contingent/temporary location), the presence of a zero copula is also available in the context of temporary locational predications, and hence a zero copula is possible for both temporary and permanent locations. The observed split distribution of gāʕid and the zero copula parallels that discussed for Maltese.

Levantine region
Above we have demonstrated that locative copula uses, with a possible extension to some non-locational predications as well, as in Libyan Arabic, is present in dialects other than Maltese, with a concomitant loss of the central lexical meaning of 'sitting'. This lexical meaning is preserved in some other dialects. The question arises as to whether the development of the locative copula use goes hand in hand with the loss of the 'sitting' meaning for gāʕid 'sit.act.ptcp'. We will below see that this is not a necessary prerequisite and indeed that gāʕid is synchronically emerging as a copula in the locative constructions of a number of vernaculars where gāʕid, as well as its associated verbform, concurrently still maintain their lexical meaning 'sitting' and 'sit', respectively. The example in (44), from Palestinian Arabic (specifically Kufr al-labad, Tulkarem), illustrates the ambiguity which results synchronically from the development of gāʕid as a locative copula and the concurrent maintenance of the lexical 'sitting' meaning in this variety. 17 (44) Palestinian Arabic (pc, Mohammed Al-labadi) in-niswān kāʕd-at barra def-woman.pl sit.act.ptcp-plf outside 'The women are sitting outside.' 'The women are outside.' Examples from the Levantine region denoting the emergence of a copula function include (45), denoting an ad hoc temporal location, in Negev Arabic. Further Palestinian data in (46) illustrates how beyond temporary locational predications (such as (44)), time-stable ones can also appear in the context of the optional use of kāʕid. 18 (45) Negev Arabic (Henkin 2010: 138) has-sammāk alliy gāʕid ʕala ǰanb al-baħar dem.def-fisherman who be.act.ptcp.sgm on side def-sea 'this fisherman who is by the sea' Use of this form is equally possible in negative clauses involving a time-stable locational predication, as in (47) (the negative marker miš may come before or after the copula, but appears only once).
(50) a. Kuwaiti Arabic ʔana (gāʕd-a) fil-mūl I be.act.ptcp-sgf in.def-mall 'I am at the mall.' b. Kuwaiti Arabic li-sħūn (gāʕd-a) ğiddām-ik def-plate.pl be.act.ptcp-sgf in front-2sgm.gen 'The plates are in front of you.' c. Kuwaiti Arabic il-akil (gāʕid) bis-saħan def-food.sgm be.act.ptcp.sgm in.def-plate.sgm 'The food is in the plate.' The restriction to temporary locations is shown by the ungrammaticality of the following examples, if the copula gāʕid is used.
(51) a. Kuwaiti Arabic ʔingiltra (*gāʕd-a) fi ɣarb ʔorobba England.sgf be.act.ptcp-sgf in West Europe Intended: 'England is in the West of Europe.' b. Kuwaiti Arabic iš-šarkiyya (*gāʕd-a) fi šāriʕ … def-company.sgf be.act.ptcp-sgf in street … Intended: 'The company is in … street.' Further evidence illustrating that the use of gāʕid does not extend to properties, whether permanent, or temporary, in Gulf dialects, here represented by Kuwaiti, is the ungrammaticality of the data in (52) (pc, Duha Alaskar).

Data summary
In this section we have suggested that beyond the phenomenon of desemanticisation of the lexical predicate into a cluster of meanings in the general domain of 'remain' or 'stay' (continue to be at location), gāʕid has developed a copula function within predicational locative structures across non-peripheral/core Arabic vernaculars very similar to the grammaticalisation of gāʕid as a copula in (peripheral?) Maltese. Some vernaculars permit both temporary/contingent and permanent/stable locations with gāʕid. Others, such as Kuwaiti, distinguish between temporary/contingent locations using a null copula or gāʕid, and permanent locations, where gāʕid cannot figure. We have also pointed to possible evidence for the extension of this locational copula strategy beyond cases of locational predication in Libyan and in Urban Hijazi. The distribution of what we have argued to be copula uses across this range of dialects indicates that this grammaticalisation is found both in vernaculars where gāʕid maintains, and in those where it has lost, its original lexical posture meaning of 'sitting'. Table 3 provides a summary overview of the data presented in the subsections above.

Implications as to grammaticalisation
While the characterisation in §5.5 summarises the data which we have argued support our claim that an additional copula is emergent within the copula systems of Arabic vernaculars, in what follows we consider what the ramifications of this data are from a diachronic perspective. That is, we seek to understand how the grammaticalisation of a copula that stands in both a morphosyntactic and semantic contrast with the zero copula strategy and the pronominal copula may have come about and developed in the vernaculars. Given the lack of a historical written record for vernacular Arabic, and the fact that this innovation also does not figure in Classical Arabic texts, our methodology in addressing this question is essentially comparative, considering the variation across the different Arabic varieties, but also informed by a typological perspective.
We have argued above that data from a considerable number of different Arabic varieties supports the view that the pre-existing split copula system has undergone further complexification with the emergence of an additional copula form so that the resultant system marks the sorts of semantic distinctions among different types of eventualities which have been described for other copula systems (such as those of some Celtic and Romance languages), often under the label of the distinction between stage-level and individual-level predication. 21 The backdrop to the innovation is a copula system with a two-way choice between the null and pronominal copula in the present tense. Following the recruitment of the posture active participle gāʕid into the system, a three-way split copula system in the present tense emerges. If we consider the distribution of data across the different dialects to be indicative of the trajectory of change in progress, the most striking observation is that all of these dialects allow the presence of the emergent copula with temporary/contingent locations. This possibility remains in free variation with the zero copula strategy. In Maltese, on the other hand, the use of the copula qiegħed in such structures is notably itself becoming the default strategy. Beyond this core, there is variability in the occurrence of the newly grammaticalised copula gāʕid in locative predicational structures: it is not the case that both time-stable or temporary locational anchorings are found with the newly grammaticalised copula in all dialects, or that inanimate subjects are necessarily found across the board. This sort of variability is of course in the very nature of change in progress.
As a very first approximation, this distribution appears to align itself with what is observed crosslinguistically from a typologically diverse set of languages. First, suppletion and renewal of copula elements is a common phenomenon, within and beyond Indo-European (Irslinger to appear: 6). Second, posture verbs are found crosslinguistically as a source of copula elements (Lesuisse & Lemmens 2018: 44, Devitt 1990. Third, crosslinguistically, it is a very common pattern for languages to encode nominal predication in a distinct manner from locational predication (Stassen 1996: 482, Irslinger to appear: 38), and bodily posture verbs are frequent sources for the encoding of locational predication 21 A reviewer has suggested to us that there might be similarities between the split copula system of Arabic which we describe here and the split present tense marking of Marathi as discussed by Deo (2019). This is a very interesting suggestion which deserves further investigation. However there are some significant differences. In the Marathi system which Deo describes, present tense sentences obligatorily mark the contrast between particular (event in progress, deictic) and characterising (habitual or generic) claims by the choice of (copula/auxiliary) verb, and this pattern is found in copular clauses and also in periphrastic aspectual constructions. Deo argues that the choice of a particular specialised auxiliary (āhe) anchors the interpretation of a clause to the time and world of utterance. Hence Marathi lexicalises a distinction between particular and characterising claims which is covert in languages like English. A point of commonality between the Marathi data and the Arabic patterns which we discuss is that the innovated, specialised present tense auxiliary derives historically from the verb acch 'sit', however the contrast introduced into the system differs in a number of respects from the one we see in Arabic, both in terms of the semantic distinctions it encodes and its syntactic domain of application. We leave further investigation of this suggestion for future work. (Newman 2002: 7). The suggested trajectory which we envisage for Arabic, rooted in the salience of the locational element of the meaning of a posture verb is hence consistent with what we know about the diachronic development of copulas from posture verbs crosslinguistically. A case in point is the grammaticalisation of the Portuguese, Catalan and Spanish copula and auxiliary estar from Latin stāre 'stand' and its gradual encroachment on ser, a well-researched case of posture verb grammaticalisation, where locational predication has played a key role (see e.g. Falk 1979, Vañó-Cerdá 1982, Remberger & González-Vilbazo 2007, Brucart 2012, Carvalho 2010, and many others). The historical record here supports a trajectory in which the newly grammaticalising element (estar) first established its place alongside ser in locative constructions, and then extends to other uses, as Batllori & Roca (2012: 86) observe: "We can see that in the twelfth century there is feature syncretism concerning the use of ser and estar to express the same value only in locative constructions, whereas in the thirteenth century it [estar] extends to stage-level copulative, resultative passive, and existential sentences … a syntactic change that conveys replacement of ser by estar is taking place progressively" [in locatives and stage-level predicate copulatives] Batllori & Roca (2012: 86).
The salience of the locational element is pinpointed as a key factor in the development of copula forms in a range of languages, including Spanish and Turkish in Devitt (1990). The grammaticalisation path which is at the core of his proposal is shown in (55), which takes account of the fact that a language may go on to develop a general copula. For Turkish, which does not generally make use of a copula in the present tense, Devitt (1990) suggests that the notion of temporariness has led to the development of a modal, presuppositional flavour associated with the use of the addition of the enclitic -dir, itself derived from the posture verb meaning 'stand', as shown in (56)  In the light of these considerations and the central role of locative predications in the data we have presented, we suggest that a natural hypothesis is that the grammaticalisation is triggered primarily through a semantic extension from the encoding of mere 'sitting' to 'be located somewhere', where a PP predicate is most natural. This eventually gave rise to the copula + locative PP combination, alongside the pre-existing zero copula structures.
Irrespective of the (internal) distinct stages the different Arabic dialects display, in their grammaticalisation and establishment of gāʕid as a locative copula, there is clear evidence from the same dialects for further extension to a general contingent/ad hoc marker, as it comes to express particular/temporary states. Hence we suggest that the Arabic dialects provide evidence for the cline of incremental change and grammaticalisation shown in (57), although we leave open for further research a more fine-grained understanding of the temporally-anchored nature of the predicates.
(57) posture > locative > copula with a verb copula temporary sense It should not be taken as a deficiency to the path being posited here that a further developmental extension to a temporary state function of the copula follows the prior establishment of the locative function of the copula, independent of the variation observed in the use of the locative copula itself. Rather, it is in fact in line with observations from different Romance languages with split copula systems, where fine-grained studies (Remberger & González-Vilbazo 2007;Batllori & Roca 2012) of these languages reveal subtle differences over the choice of copula, and which do not invalidate the general trajectory proposed. While for instance Portuguese and Spanish both make use of the split between the copulas ser 'be' and estar 'contingent be' to express a distinction between permanent versus temporary states in the context of adjectival predicates, their individual use of the copulas in locative structures differs. While Spanish makes use of estar in all locative contexts, Portuguese still uses both copulas in locative contexts, such that ser is maintained to mark permanent locations, while estar is used in the contexts of temporary physical locations (58). 22 (58) a. Portuguese (Devitt 1990: 108) A casa e no Flamengo. def house is(ser) in.def Flamengo 'The house is in Flamengo.' b. Portuguese (Devitt 1990: 108) João está em casa. João is(estar) in house 'João is in the house.' The split in the locative constructions in Portuguese thus essentially reflects the same split that obtains in the context of adjectival predicates. A similar, if not exactly parallel split use of the copulas in locative constructions, is also true of Catalan (see Batllori & Roca 2012). The pattern of difference which we see between these Romance languages, including in particular the locative use of estar in Spanish, is relevant to the use of the new copula with all locational predicates in Maltese. These differences show that as the languages or dialects develop along the same grammaticalisation cline, different nuances or components of meaning become or remain focal. For some discussion of this in relation to Romance, see Remberger & González-Vilbazo (2007).
The path in (57) that we reconstruct as the developmental path for Arabic involves a change from an active participial of a posture predicate to a copula with various functions and domains of applicability, with variability across the dialects. This path of change, we claim, did not take place on its own. Rather, there is evidence of a distinct but related development in which the same posture predicate maintains its status as a lexical predicate, yet undergoes distinct stages of semantic bleaching as hypothesised in (59). These different stages are posited on the basis of the range of variation that exists across the dialects, where for instance we observe the loss of a 'sitting' reading in Libyan and Chadian, varieties which use the same lexical form to mean 'exist, be situated'. On the other hand, Levantine and Gulf dialects make use of gāʕid with both a maintenance of the original 'sitting' sense, as well as the more desemanticised sense of 'staying, remaining'. In these dialects a further bleached existential reading is however not (as yet) recorded.
'sitting' posture predicate > 'staying, remaining' > 'existential be' If (59) is on the right track, it displays key parallels with the cline in (57) as the 'staying, remaining' is clearly closely related to the locative copula part of the latter path. We keep (59) distinct from (57) for our Arabic data, because the former are not copula functions of gāʕid, but rather, bleached lexical extensions, and the development of an existential use does not in principle need to be correlated with the emergence of a predicative copula. However, the fact that those dialects which do have the existential use also have the copula use is suggestive of a close connection, raising the possibility that the locative copula stage in the trajectory in (57) might actually encompass two stages, the first of which involves the bleached lexical extension to a 'stay, remain' meaning which also underpins the development of the existential usage. This possibility is discussed in more detail in Camilleri & Sadler (under review).

Parallel split systems internal to Arabic
A temporary/permanent or stage-level/individual-level distinction in the domain of copula constructions has been said to have grammaticalised in other peripheral varieties of Arabic, such as the Anatolian variety of Sason Arabic (Akkuş 2016;Akkuş & Benmamoun 2016). (See also the descriptions of Qartmin and Kinderib in Jastrow 1978;Jastrow 1999). Akkuş (2016) shows that Sason Arabic has extended the use of the past tense forms of copula 'be' to the present tense in the non-3rd person, but shows an alternation between two sets of forms in the 3rd person. Table 4 gives the paradigm of the copula system in Sason. A set of forms corresponding to cliticised forms of the 3rd person pronoun are used as general copula predicators (60), and additionally, a set of forms which Akkuş takes to be derived from the verbal copula, are available, but restricted to use with temporary or stage-level properties, as illustrated in the contrast in (61).

Conclusion
In this paper we have argued that a number of Arabic vernaculars are developing an additional split in the copula system with the emergence of a new copula form derived from the active participle of a posture verb root with the etymological meaning of 'sit', gāʕid (and its associated variant forms) that has itself also bleached and desemanticised, and given rise to additional lexical senses associated with this active participle form. These innovations present across a number of Arabic vernaculars lead to a copula system akin to the split system which has emerged in Maltese. We have shown that this split, and its further entrenchment within a system of a given variety, is unrelated to whether we have complete loss of the postural, lexical meaning of gāʕid or not. We have suggested that Maltese and Urban Hijazi may be seen as displaying parallel developments in the copula system, even if the details of the copula's grammaticalisation in both varieties is not the same; Maltese has broadly lost the lexical postural reading for the active participle form, which has purely grammatical meanings, while Urban Hijazi maintains lexical uses of the active participle associated with the lexical meaning 'sit', as well as other more bleached uses. Furthermore, while Maltese demonstrates evidence for the grammaticalisation of qiegħed as a locative copula across the board, this is not the case in Urban Hijazi, where we only find evidence for the use of gāʕid in particular/temporallyanchored locations. In arguing that the Arabic dialects are developing or have developed an additional copula based on a form of a posture verb, we make the first explicit claim that such a grammaticalisation has taken place in Semitic. We have suggested a grammaticalisation path leading to this copula form, based on a cross-dialectal comparative method. This aligns with the core essence of parallel developmental paths hypothesised for other typologically-distinct languages, particularly ones with a stronger written tradition.
Looking beyond the grammaticalisation of the copula derived from a posture verb root, we have drawn a parallel with two other emerging split copula systems in other Arabic varieties, involving different grammaticalised items. While we see different degrees of grammaticalisation, and differences from variety to variety in the precise domain of the new copula, we see that the core characteristics determining the distribution implicate the distinctions between locational and non-locational predication, and inherent, i.e. characteristic versus temporally-dependent properties.