Possible Solutions for Long-standing Problems Involving Old English Nominal Forms

Solutions are presented, most involving Celtic infl uences in West Germanic (WG) during the ancient period, for some long-standing problems involving nominal forms. The M N-SG forms of /n/-stems in WG may be seen as due to loss of /-n/ (in analogical /-ͻͻn/) having happened after shortening. Apparent replacement of the F G-SG by the D-SG in WG may be seen as due to the D-SG of the F personal pronoun being employed, in “external possession”, as a kind of indirect refl exive, after /siin-/ became limited (for reasons connected with Celtic infl uence) to M SG meaning. This case has analogues in Romance. Final /-s/ in the A-PL of M /a/-stems may be seen as due to Celtic infl uence causing /-nz/ to be replaced by /-ns/.


Introduction
In treating the development of nominal forms in West Germanic (WG), the conventional wisdom fails to explain (in a sensible manner) several important cases. After about 150 years of assiduous and dutiful eff ort, some OE nominal forms still have no good explanation. Since all such cases belong to the history of English, all have been regarded as fair game here, regardless of whether the solutions proposed have wider applicability. The most important cases are 1) the N-SG of M /n/-stems, 2) the G-SG of F /oo/-stems, and 3) the N-PL of M /a/-stems in northerly WG. In presenting the facts it is often necessary to distinguish between northerly WG (N-WG) and southerly WG (S-WG). Old English (almost always joined by Old Frisian) is always northerly, and Old High German is always southerly. Old Dutch (OD) and Old Saxon (OS) can show either northerly or southerly forms, the details rarely having much relevance. represent the fi rst wave of Germanic conquest.) In a situation where the archeological evidence admits of various interpretations, a historical linguist is free to prefer whatever interpretation makes the best fi t with the linguistic evidence. In the present case, this is that the area in question belonged to Celtic (Barnes 2009, 26-27) or rather "Para-Celtic". No doubt "Para-Celtic" is the most appropriate term, technically speaking, since the IE place-names of the area do not show the characteristic sound-changes (like loss of /p/) that defi ne true Celtic. Nor does the material culture of the area show artifacts of the Hallstatt and La Tène types, which within the domain of archeology defi ne true Celtic. But that could well be because the area once belonged to a "Pre-Celtic" culture that, cut off from other Celtic after it was conquered by Germans, did not participate in the later changes of linguistic and material culture that allow us to identify an area as belonging to true Celtic.
As for the linguistic evidence, this includes not only the toponymic evidence but also the evidence of grammatical features, which is to say the areal evidence. In fact grammatical resemblances to Celtic are found in essentially all of the territory of WG (as of about 750 A.D.). This is true not only in Britain and SW Germany, where the pre-Germanic population clearly was Celtic-speaking, but also in the more northerly area where it supposedly was not. Furthermore, resemblances to Celtic appear to be more common in N-WG than in S-WG. Though it is diffi cult to prove a negative, there appears to be only one case, wide-spread /s-/ in 3 rd person pronouns, where a possible Celticism appears in S-WG but not in N-WG, and here it may well be that /h-/ in N-WG was created by a later evidence-erasing innovation. As the pattern in the areal evidence is the exact opposite of what the conventional wisdom would lead us to expect, we must suspect that the conventional wisdom is wrong.
A list of (easily explained) apparent Celticisms that occur in N-WG but not in S-WG will now be presented. Some of these will come up below. Since the exponential math inherent in assessing the likelihood of coincidence means that it is better to present numerous brief cases than a few detailed cases, that is what has been done.
1) Complete loss of the refl exive/non-refl exive distinction in pronouns. There seems to be general agreement that OD and OS underwent this loss before regaining the accusative from S-WG. Refl exive pronouns were completely absent in Celtic (Vennemann 2013, 121), this being a characteristic innovation of Celtic. 2) Loss of /-t/ in /ist/. A change of /st/ to /ss/ (later reduced to /-s/ in fi nal position) appears to be lautgestzlich in Celtic (Schrijver 1995, 403, 428). Thus all textually attested Celtic shows no /t/ in its various refl exes of PIE /esti/ 'is' (Lewis andPedersen [1961]1989, 318-321). The cognancy of Germanic /isti/ and Celtic /issi/ would have been clear to Celts secondarily acquiring WG, providing a motivation for loss of /t/.
This occurs in both Irish and Brittonic (Lewis andPedersen [1961]1989, 193-195, 203-205), not to mention also in Old French (Kibler 1984, 74), where it is plausibly seen as due to Gaulish sub-stratal infl uence. In AF and Dutch (Donaldson 1983, 171-172;Bremmer 2009, 56), 3 rd pronouns evidently bifurcated into stressed forms with /h-/ and unstressed forms without /h-/. OS seems to show the older state of aff airs, with /h-/ only in nominatives. 8) Initial voiced fricatives. Since the evidence of Romance seems to indicate (indirectly) that Gallo-Brittonic developed voiced initial (and medial) fricatives both rather early and before it developed voiceless initial fricatives, voicing of initial (and medial) fri-catives in Dutch (Donaldson 1983, 150-151) and (southern, Middle) English (Mossé 1952, 38-39) may be regarded as due to Celtic infl uence. 9) Non-aspiration of voiceless plosives. In continental WG, this occurs only in (non-NE) Dutch and nearby forms of Low German (Schrijver 2014, 123). Much of the Dutch part of this area belongs to an area that Schrijver (2014, 141) regards as having once belonged to proper Celtic, and the rest belonged to "Para-Celtic". It seems probable that both proper Celtic (in this area) and "Para-Celtic" had non-aspirated voiceless plosives, passing this feature on to local forms of WG during secondary acquisition.
The combined implication of these cases should be taken seriously: the Pre-Germanic IE language of the N-WG area was much closer to Celtic. It will be argued below that there are additional cases where an odd innovation of WG can be explained by reference to a feature that, far from being just vaguely IE, is in fact identifi ably Celtic. Since having to repeatedly use terms like "Celtic or Para-Celtic", though technically correct, would be very awkward, the term "Celtic" will be employed with this meaning from here on.

Tri-moraic /-ͻͻͻ/ in the N-SG of /n/-stems
The recent conventional wisdom (Stiles 1988;Jasanoff 2002) is that in the N-SG of M /n/-stems bi-moraic /-ͻͻ/ became tri-moraic /-ͻͻͻ/ by phonological change. But even a strong supporter (Ringe 2006, 74) calls the supposed development of trimoraic /-ͻͻͻ/ "very surprising". Though there is of course no problem with positing tri-moraic Vs in cases where they are morphologically warranted, as with /-ͻͻ-ͻm/ in the G-PL of F thematics, the N-SG of M /n/-stems does not qualify in this regard. From its home in the /n/-stems, where it is clearly ad hoc, the theory of tri-moraic /-ͻͻͻ/ has spread to various other cases. In these, the fact that no need to posit tri-moraic /-ͻͻͻ/ had previously been felt indicates that what we have here is desire to create plausible deniability about the original theory being ad hoc. Over the years, the result of additional "discoveries" involving tri-moraic Vs (without morphological warrant) has been a theory that is both problematic in its core case and suspiciously complex. Any theory about how the /n/-stems of Germanic developed must explain the following two cardinal facts. The fi rst is that in WG the M N-SG, pointing back to /-ͻͻ/, has one more mora than would be expected to result from PIE /-oo/. (It also does not fall together with the result of PIE /-aa/ in the N-SG of F thematics.) The second is that the F N-SG and the N N/A-SG are always (except where the alternative F N-SG /-ii/ is found) the same. The conventional wisdom attempts to explain the fi rst of these facts by positing ad hoc tri-moraic /ͻͻͻ/, and does not attempt to explain the second at all, presenting the impression that it is merely coincidental. But if WG developed M N-SG /-ͻͻn/ and N N/A-SG /-ͻn/, for the same analogical reasons that Greek developed M N-SG /-oon/ and N N/A /-on/, then we have a possible explanation for why the M N-SG in WG would seem to be one mora too long: /-n/ would shield /ͻͻ/ from shortening. Likewise in the F /n/-stems, if these were created after shortening, the fi rst F N-SG might well have been the same as the N N/A-SG /-ͻn/, or at least similar enough to be taken as such.
Whether such a scenario could work depends on the development of fi nal nasals in Germanic. It is not controversial that /-m/ in monosyllables became /-n/. As cases of this type have no relevance there, they will be ignored from here on. For other cases, the long-standing conventional wisdom (Wright [1910(Wright [ ]1954Ringe 2006, 85-86) is that /-m/ became /-n/, and that all /-n/ was early on lost, with nasalization of long Vs at least. Since common loss of fi nal nasals is what this amounts to, that is what it will be called below. But it is far from clear that common loss of fi nal nasals actually occurred, and it will be seen that there is no need to posit nasalization of unstressed Vs before lost nasals, which would violate the general rule that unstressed Vs show fewer distinctions than do stressed Vs. Cases of fi nal /-n/ in PIE are in any event so rare and uncertain that there is no proof that fi nal /-n/ did in fact fall together with fi nal /-m/.
If we assume that WG (at least) developed M N-SG /-ͻͻn/, and that all Germanic developed N N/A-SG /-ͻn/, by essentially the same analogies that motivated M N-SG /-oon/ and N N/A-SG /-on/ in Greek, and ask whether there is any evidence that common loss of fi nal nasals occurred in WG, the answer is no. Using OE as our example language, /-ͻͻm/ (A-SG of F thematics) appears as /-e/ << /-ͻ/, whereas /-ͻͻn/ (N-SG of M /n/-stems) appears as /-a/ << /-ͻͻ/. Similarly, /-ͻm (A-SG of M thematics) appears as /-/ << /-ͻ/, whereas /-ͻn/ (N-SG of N /n/-stems) appears as /-e/ << /-ͻͻ/. Under this scenario, forms with /-m/ are regularly one mora shorter than forms with /-n/, and /-ͻͻ/ has two diff erent outcomes, depending on whether it was followed by /-m/ or /-n/. Thus if the unremarkable analogies posited above occurred, we have not only no evidence that common loss of fi nal nasals did occur, but positive evidence that it did not. The evidence of WG may be seen as resulting from the following changes having occurred (at least in WG) in the following order: 1) loss of /-m/, 2) shortening of fi nal Vs, and 3) loss of /-n/. To revisit the evidence of OE, 1) /-ͻͻn/ would become /-a/, 2) /-ͻͻm/ and /-ͻn/ would become /-e/, and 3) /-ͻm/ would become /-/. Since such forms are what we fi nd, we must suspect that this series of changes is what occurred. But if so, common loss of fi nal nasals did not occur.
As for how the apparent rule of identity between F N-SG and N N-SG developed, the best possibility appears to be 1) that the fi rst Fs developed after shortening, and 2) that there was (in non-East Germanic) a change of unstressed /ͻ/ to /u/ not only before moraic /m/ (Ringe and Taylor 2014, 17) but also before (at least some) moraic /n/. 1 Technically speaking, this change was really loss of possible contrast between unstressed /ͻ/ and /u/ before nasals, which is hardly surprising. In non-East Germanic, N N-SG /-ͻn/ ~ /-un/ would be indistinguishable from F N-SG /-un/ ~ /-ͻn/. In East Germanic, the two would also be the same, just with clear /-ͻn/ instead of muddled /-ͻn/ ~ /-un/. Either way, the result in all Germanic would be identity, creating a basis for a rule of identity.
Three loose ends remain to be tied up (or not, in the case of the last).
The idea that /-oo/ in the F/N N-SG of Gothic is phonological rather than analogical in origin involves positing the "surprising" change of /-ͻͻ/ to /-ͻͻͻ/, which will not of course be done here. Gothic F/N N-SG /-oo/, identical with the result of /-ͻͻ.ͻm/ in the G-PL of F thematics, is simply too long to have any plausible source in Early Germanic, and must instead have the same analogical source as /-oo/ in Runic (Haugen 1976, 126). The fact that the two inherited /n/-stems with N-SGs in M-looking /-ͻͻ/, 'name' and 'seed' (Ringe 2006, 275), developed M gender in WG is hardly surprising. In Gothic, the other way of resolving the contradiction was taken: 'name' retained N gender, but developed a regular N N/A-SG in /-ͻn/, later altered to /-ͻͻ/ in lock-step with the F. Though re-development of /ͻͻ/ creates the impression that /ͻͻ/ existed all along, this impression is an illusion. The similarity between Gothic /namoo/ (N) and pre-OHG /namoo/ (M) is merely coincidental, and as such has no implications for Early Germanic.
As has long been known, or at least strongly suspected (Wright [1910(Wright [ ]1954, various Gothic adverbials in /-oo/ or /-ee/ can be seen as showing long Vs not because their Vs were originally tri-moraic but rather because they still had (when fi nal long Vs were shortened) /-t/ from ablative /-d/. Nothing in such forms indicates tri-moraic Vs that would create plausible deniability about trimoraic /ͻͻͻ/ in the M N-SG of /n/-stems being ad hoc.
Reconstruction of the M N-SG in non-WG, more diffi cult than relevant, has not been attempted. Suffi ce to say that if Prokosch (1939, 251) is right, M /-ɛ/ in Pre-Gothic could provide an explanation for Gothic G-PL /-ɛɛ/ > /-ee/: analogy with F N-SG /-ͻ/ and G-PL /-ͻͻ/.
It seems advisable to present a table showing that the sound-changes posited do not lead to wrong results, at least in the major cases treated. (As for minor cases not treated, "proving a negative" about these would be very diffi cult.) The table is intended to apply only to WG, though some side notes are made about non-WG. Changes have been simplifi ed somewhat in order to avoid irrelevant complications. The meanings of the column labels employed are as follows. 1: A-SG of M thematics, N/A-SG of N thematics; 2: N-SG of M /n/-stems; 3: A-SG of F thematics; 4: N-SG of F thematics, N/A-PL of N thematics, 1SG present of many Vs; 5: N/A-SG of N /n/-stems, (eventual) N-SG of F /n/-stems; 6: G-PL of F thematics; 7: N-PL of M thematics, N-PL of F thematics, G-SG of F thematics; 8: A-PL of M thematics. Changes have been put in bold. Preceding states are repeated before every set of changes, and zero as an ending has been represented by "⃝". The case of the infi nitive, which is diffi cult, will be treated below.
Mora Loss. Final unstressed Vs (except /u/) lose one mora. 2 Soon afterwards, F /n/-stems are created, with N-SG /-un/. Since /-un/ and /-ͻn/ are not distinguishable, the new F N-SG is in eff ect the same as the old N N-SG (case 5), and a rule of identity develops. In N-WG, /-nz/ becomes /-ns/. (This case will be treated in section 4.) Column 8 must now be split into two columns, 8a and 8b.
(It is quite possible that /-z/ after Vs was not lost at the same time as /-z/ after /n/). In N-WG, /n/ in /-ns/ is lost, with moraic continuity.
The complete table is as follows: What is most important here is what does not appear: tri-moraic Vs. Reasons to consider this a desideratum have been given above. Also worth noting as "not appearing" are nasal Vs. This too is a desideratum: the idea that Early Germanic had nasal Vs only in unstressed Vs violates (as has been noted) the general rule that stressed Vs show more distinctions. 3 It is worth noting that, without nasalization of unstressed Vs, the conventional wisdom loses its explanation for the diff erence of development between F N-SG /-ͻͻ/ and F A-SG /-ͻͻm/.
If the infi nitive ending in Pre-Germanic was /-onom/, the scenario given above wrongly predicts that we should fi nd infi nitives in /-a/ < /-ͻ/. It is therefore necessary to posit that the infi nitive ending was something else. But fi rst some comments on /-onom/ are appropriate. In the older IE languages that show a variety of infi nitive endings, which is to say Vedic Sanskrit, Homeric Greek, and Old Irish, a form pointing back to /-onom/ appears in only one verb: 'milking' in Old Irish (Thurneysen 1946, 454). Thus there is little reason to believe that /-onom/ existed in PIE A better possibility appears to be that the original ending was /-omnom/, with the same /m-n/ that was employed to form middle participles and abstract nouns (including verbal nouns) in PIE, and which appears in some infi nitives in Homeric Greek (Sihler 1995, 618, 288, 609). A dissimilatory change of /mn/ to /md/, followed by a change of /md/ to /nd/, appears to lie behind Latin "secundus" (Sihler 1995, 627). If the same thing happened in Pre-Germanic, then the initial developments would be /-ͻntͻm/ > /-ͻntͻ/ > /-ͻnt/ > /-ͻn/ > /-an/.
To sum up, the relevant changes were as follows: 1) creation of M N-SG /-ͻͻn/ in WG (at least) and N N/A-SG /-ͻn/ in all Germanic, 2) loss of fi nal /-m/, 3) mora loss, 4) creation of a) F /n/-stems, and b) the rule of identity between F N-SG and N N/A-SG, and 5) loss of fi nal /-n/. Such a scenario explains, without recourse to "surprising" changes, the two cardinal facts noted at the outset: 1) why the F N-SG is (in WG) one mora shorter than the M, and 2) why the F N-SG is (in all Germanic) the same as the N N-SG, apparently by rule. Negatively speaking, such a scenario involves denying the following changes: 1) change of fi nal /-m/ to /-n/, 2) loss of fi nal /-n/ before mora loss, 3) development of nasalized Vs, 4) existence of tri-moraic Vs without morphological warrant, and 5) merely coincidental identity between the F N-SG and N N-SG of /n/-stems. It seems better simply to posit that /-n/ developed in the M N-SG of WG (at least) and in the N N/A-SG of all Germanic, and that fi nal /-n/ was lost after mora loss.

The G-SG of F Thematics in West Germanic
It has never been explained why the G-SG of F /ͻͻ/-stems in WG does not simply continue the refl ex of Early Germanic /-ͻͻz/, as do /-oos/ in East Germanic and /-ar/ in North Germanic (Wright [1910(Wright [ ]1954Gordon [1927Gordon [ ]1957. The WG forms should appear as northerly /-a/ and southerly /-o/. Hogg and Fulk (2011, 30-31) admit this, and off er no explanation as to why G-SG /-a/ is rare in OE. By contrast Ringe and Taylor (2014, 58-60), following Stiles (1988, 129-130), deny that the WG forms should have been northerly /-a/ and southerly /-o/, positing that unstressed bi-moraic /ͻͻ/ became /aa/ in some cases. But the cases cited in support are all dubious. Only three can be treated here.
First, it is improbable, on general principles, that the inherited preterit 3-SG of weak verbs was analogically replaced by the 1-SG. Nor is there any reason (not counting wishful thinking and benefi t of hindsight) to believe with Ringe (2006, 148) that 1-SG /-eem/ would be expected to become /-oo/. More probable is that the 1-SG and 3-SG fell together by analogy going the other way, from 3-SG /dɛdɛ/ (with fi nal stress). Second, the N-PL of F thematics, which Ringe and Taylor attempt to explain as diff ering from the G-SG by having three moras instead of two, probably had only two. The older IE languages never (Sihler 1995, 267-271) show F thematic forms in /-s/ that can only be explained by positing /ah 2 / 4 plus a vocalic ending that would add a 3rd mora. For example, there is no evidence pointing back to A-PL /-ah 2 ṇs/. The attested forms point back to /-aans/, variously resolved as /-aas/ or /-ans/, and it is evident that in the A-PL at least /-ah 2 -/ became /-aa-/ early enough that C-initial endings were employed (except in the G-PL, which was a late innovation). Third, M A-SG pronominal forms appearing to point back to nasalized /-ͻͻ/ might go back rather to /-ͻt/ < /-ad/, since /-t/ would (unless Ringe (2006, 144) is wrong about the ordering of apocope) protect /ͻ/ from apocope. If so, long /oo/ and /ee/ before /x/ in Gothic would have to be due to lengthening before /x/, but there does not appear to be anything decisive against that. There is no compelling reason to think that bi-moraic /-ͻͻ-/ became /-aa-/ in Late Germanic.
The G-SG of F thematics in WG appears to go back (where instrumentals in /-u/ have not intruded) to the D-SG (Ellis 1966, 31). The one exception, abstracts with G-SG /-ungɑ/, is pretty clearly due to assimilation of /-ae/ to /-ɑ/ after /-ung/ (Hogg and Fulk 2011, 31). What may be called "instrumental intrusion" will be ignored from here on, except to note that, as instrumental forms are most frequently found as datives, instrumental intrusion in the genitive is itself a form of "dative intrusion". The dative ending (in origin a locative) was /-i/, so that the D-SG of F thematics should have been /-ͻͻi/, which is to say the F thematic stem V /ͻ/ (after shortening) plus the M thematic D-SG ending /-ͻi/. No doubt /-ͻͻi/ > /-ooi/ is the origin of forms pointing back to /-uu/ in Norse. In other Germanic, it is evident that /-ͻͻi/ was shortened before /ͻͻ/ became /oo/. In East Germanic, this must have happened after /-ͻi/ > /-ai/ became /-ee/ >> /-a/.
In Gothic, F D-SG /-ͻi/ became /-ai/ (Wright [1910(Wright [ ]1954. Since in OHG the D-SG of F thematics is /-a/ (Ellis 1966, 31), not the same as M /-e/ from earlier /-ai/ (Ellis 1966, 28), the F must have a diff erent origin. It seems probable that shortened /-ͻi/ > /-ai/ simply lost its /-i/. Since /-a/ in OHG as a rule corresponds to /-ae/ in OE, the simplest interpretation is that the same thing happened in N-WG.
For OE, a literal interpretation of the evidence would indicate that /-e/ in the M D-SG became /-ae/, falling together with F /-ae/, with a later change of /-ae/ to /-e/. But a back and forth change of /-e/ to /-ae/ to /-e/ must arouse some suspicion, and critical examination reveals no compelling evidence that "-ae/-ae" and "-e" were in fact in contrast in the earliest glossaries, most notably Épinal. It seems probable that unstressed /-e/ in OE had already become centralized enough that preceding Cs struck Irish ears as more back than front, so that "-ae", which to Irish eyes meant /e/ preceded by a back C, would be the appropriate spelling. 5 Since to Irish ears /-ae/ in OE also seemed to be /-e/ preceded by a back C, contrast between "-ae" and "-e" was not possible (in the original system). To the native English, it would seem that /-e/ and /-ae/ were both, for some strange reason, to be spelled as "-ae". All in all, it seems most probable that the F /-ae/ and M /-e/ fell together only with the later change of /-ae/ to /-e/.
The idea that the G-SG of F thematics is exactly what it looks like, the old D-SG employed as a new G-SG, is not new. Hogg and Fulk (2011, 31) note that it was argued by Flasdieck (1930), and it is presented (in passing) as a plain fact by Ellis (1966, 31) for OHG. Yet it has not won much acceptance. Hogg and Fulk (2011, 31) dismiss the idea as "unilluminating", an implicit admission that the theory works technically. It is not as if there is no connection between the meanings 'dative' and 'possession', as is suffi ciently conveyed by the phrase "dative of possession", and random divergence might be why this connection had eff ects only in WG. But random limitation to F thematics is problematic: any purely semantic motivation should have applied across all declensional classes. This must be what Hogg and Fulk object to. The question that must be answered is this: why did the D-SG drive out the G-SG in WG only and in F thematics only?
An answer to this question may be found lurking in a corner of the grammar that might at fi rst appear to have no possible relevance: loss of the refl exive/ non-refl exive distinction in genitive/possessives. The connection is by way of "external possession". This typically 1) involves a dative (or prepositional phrase) functioning as a de facto genitive to mark the possessor, and 2) is refl exive in meaning (Scholten 2018, 36-37). 6 If 1) the D-SG of the F personal pronoun began to be employed as a sort of indirect refl exive, fi lling the gap created as /siin-/ became regarded as no longer capable of expressing F SG meaning, and 2) the D-SG later lost its originally intended refl exive meaning, becoming regarded as nothing more than a new G-SG, then spread of this usage to other F thematics would result in dative intrusion.
Developments in this case cannot be understood in isolation from their larger areal context. Across a wide swath of western and northern Europe, more or less in the areas now belonging to Romance and WG, the refl exive/non-refl exive distinction had been, by the middle of the Dark Ages, either partially or totally lost. There are two main types.
In Romance and S-WG, the refl exive/non-refl exive distinction was partially lost: in genitive/possessives. As Old French is the form of Romance with the greatest potential relevance to WG, and matters are essentially similar in other Romance, Old French will be the focus from here on. In Old French, the inherited refl exive form is used in the genitive/possessive of SGs, and non-refl exive forms are used elsewhere (Mendeloff 1969, 64). In S-WG, the inherited refl exive form was used in the genitive/possessive of the M SG, and non-refl exive forms were used elsewhere (Ellis 1966, 48). In both Old French and S-WG, the forms in question are employed with both refl exive and non-refl exive meaning, though reasons will be seen below to think that this was a later development.
In N-WG, the refl exive/non-refl exive distinction was (to simplify a bit) completely lost, due to complete loss of the inherited refl exive (Ringe and Taylor 2014, 165). Though in OE the old refl exive /siin/ (oddly enough employed as a true refl exive, for all numbers) limps on in poetic/archaic usage, the impetus towards loss was clearly strong from the beginning. It is clear that OD and OS originally went with OE in this regard, though by the time of attestation both have either wholly or partially adopted the system of S-WG (Gallée 1910, 237-238;Cowan 1961, 42). Though /siin/ occurs (only as a non-clitic) in OF (Bremmer 2009, 56), the fact that it is employed in the manner of S-WG means that its appearance must be due to later infl uences from S-WG (transmitted by way of OD and OS). It is not immediately apparent whether N-WG shared early developments with S-WG. Reasons will be given below to think that it did.
Two additional facts should be noted. Old French shows a confusion of refl exive and non-refl exive pronouns (Kibler 1984, 88) that would be inconceivable in Modern French. Evidently an abortive move toward total loss of the refl exive/non-refl exive distinction was being reversed that Old French, S-WG, and N-WG all lose the dative refl exive (Ellis 1966, 48;Mendeloff 1969, 64). Since the predominant use of this must have been to express refl exive possession, its loss must have some connection with loss of the refl exive/nonrefl exive distinction in genitive/possessives. What that connection might be will be seen below.
It can hardly be stressed too strongly that even partial loss of the refl exive/ non-refl exive distinction, which should have been both clear and useful, is at best un-expected and at worst perverse. The same goes for loss of the dative refl exive. Neither one of these losses occurs in Gothic or Norse (Wright [1910(Wright [ ]1954Gordon [1927Gordon [ ]1957, which must represent the expected development. The areal evidence indicates that a motivation for both losses existed in Romance and in WG (especially N-WG), but not in non-WG. This in turn indicates something that is anathema to traditional Germanicists: external motivation. Grammatical resemblances between French (often joined by northern Italian) and continental WG are common enough that a "Charlemagne Sprachbund" has been posited (Auwera 1998). The conventional wisdom seems to be that the Charlemagne Sprachbund was created by mutual superstratal infl uences fl owing back and forth between Romance and continental WG.
But whether or not that is true in most cases (which for reasons not worth going into seems improbable), it cannot be true in the present case, for a very simple reason: nothing in the start-states of Romance or WG would provide a motivation. We would be stuck with positing an innovation without motivation, hardly a likely scenario, except for two facts. The fi rst is that one thing French, northern Italian, and WG have in common is that they all existed in territory that had once belonged to Celtic. The second is that refl exives did not exist in Celtic. Since external possession is strongly associated with refl exive meaning, it can hardly be surprising that external possession too did not (apparently) exist in Celtic, which simply employed possessive pronouns in the manner of PDE (Lewis andPedersen [1961]1989, 194-195, 204-205). As the refl exive/non-refl exive distinction is more widely lost in genitive/possessives, it seems that the distinction was, for some reason that need not detain us, more easily lost in genitive/ possessives. It is diffi cult to avoid concluding that loss, partial or total, of the refl exive/non-refl exive distinction in French, S-WG and N-WG was motivated by infl uences from Celtic.
In the PL genitive/possessives of WG, where apparently nothing happened except that the old refl exive became limited to M SG meaning, the inherited forms employed are genitives, as expected. But in the F SG, the form employed in S-WG is not the genitive but rather the dative. This is not as expected, and so requires some explanation. It seems that a semantic connection was perceived between the meanings 'refl exive' and 'dative'. This is hardly surprising, since (as has been noted) datives in external possession typically have refl exive meaning. Some examples are French "Je me lave les cheveux" 'I wash/am-washing my hair', literally 'I wash (for) me the hairs', and its F 3 rd person equivalent "Elle se lave les cheveux", 'she washes/is-washing her hair', literally 'She washes (for) herself the hairs'. (Note the accusative in place of the lost dative.) The question is why this semantic connection, which would have applied quite generally, had linguistic consequences only in the F SG.
The answer appears to be that the F-SG stood in a saliently contrastive relation with the M SG, where /siin-/ had come to be limited to M refl exive meaning. Note that if /siin-/ had already become regarded as covering both refl exive and non-refl exive meaning, there would have been no reason not to use the genitive of the F pronoun. Use of the dative instead makes sense only if the refl exive/nonrefl exive distinction was not quite dead yet. Speakers casting about for some new way of expressing F SG refl exive meaning could hardly have done better than to employ the dative of the F personal pronoun as a kind of indirect refl exive. Probably in the beginning this usage was in eff ect by analogy with non-3 rd pronouns. For the historical moment, F refl exive meaning was signaled not directly, by form, but indirectly, by case. The situation was roughly as follows:

Refl exive
Non-Refl exive M: siin-ɛsɛ F: ɛzͻ.ͻi ɛzͻͻz But in the long run this awkward system could be not maintained, and all forms of WG lost the refl exive/non-refl exive distinction in genitive/possessives. Even in a situation devoid of external infl uences, use of the old D-SG as a new G-SG might well be interpreted as nothing more than a "fashion trend" toward using the old D-SG as the new G-SG. But the situation in Old French and WG does not qualify as "devoid of external infl uences". To Celts, whose language had neither the refl exive/non-refl exive distinction nor external possession, 'wash her(D-SG) hair', intended as indirectly signaling refl exive meaning, could only be interpreted as 'wash her(G-SG) hair', without any specifi cally refl exive meaning. (The time period was before the development of defi nite articles in Germanic.) The attempt to save the refl exive/non-refl exive distinction in the F SG by using the D-SG was thus inevitably abortive.
What happened overall was evidently as follows. As Romance and WG spread into areas where the previously existing languages, whether Celtic (or, in some of the Romance area, Vasconic), did not have either the refl exive/non-refl exive distinction or external possession, both of these concepts were somewhat damaged. The dative of the refl exive was so damaged as to be completely lost. (More on this will be said in the next section.) In Romance and S-WG, both the refl exive/non-refl exive distinction (outside of genitive/possessives) and external possession were able to survive the near-death experience that followed their encounter with Celtic. As the refl exive/ non-refl exive distinction (in genitive/possessives) continued to fade away in WG, S-WG generalized /siin-/. But N-WG, where the impetus away from refl exives with /s-/ was stronger, generalized non-refl exive /ɛs-/ (with development of initial /h-/ in OE). Use of the old D-SG as a new G-SG spread from the personal pronoun fi rst to F demonstratives, then to F thematic adjectives, and fi nally to F thematic nouns. Since this process is common to all WG, it is diffi cult to avoid the conclusion that N-WG did indeed share early developments with S-WG.
If this is what happened, we have answers to three questions. The fi rst is why the F SG form used (in the personal pronoun) to express possession is not the genitive but the dative: the dative was employed in an abortive attempt to express the refl exive/non-refl exive distinction through external possession. The second is why the D-SG replaced the G-SG in F thematics only: the starting point, the personal pronoun, was a F thematic. The third is why the D-SG replaced the G-SG in WG only: WG was the only branch of Germanic that was in contact with Celtic.

Common A/D-SG forms in 1 st , 2 nd , and Refl exive Pronouns
In personal pronouns, except for 3 rd person non-refl exives, Old French and N-WG show endingless accusatives identical with the dative (Gallée 1910, 236;Cowan 1961, 42;Mendeloff 1969, 64;Hogg and Fulk 2011, 203, 205). Two matters connected with, but not really relevant to, the present case will be ignored here: 1) variation between /e/ in OE and /i/ elsewhere, and 2) non-singular non-3 rd pronouns in Germanic. In these last, development of a common accusative/ dative, which is found in Gothic and Norse (Wright [1910(Wright [ ]1954Gordon [1927Gordon [ ]1957, is clearly old. The conventional wisdom (Hogg and Fulk 2011, 203;Ringe and Taylor 2014, 86) regards loss of /-z/ > /-r/, which is to say a phonological change, as the reason that N-WG shows dative non-3 rd pronouns without /-z/ > /-r/. (Since it is not entirely clear whether it was /-z/ or /-r/ that was lost, use of "/-z/ > /-r/" seems best.) But there are problems with this idea. One is that loss of the dative refl exive /siz/ in all WG cannot of course be attributed to loss of /-z/ > /-r/ in only some WG. Thus there is at least one case where loss of the dative was not phonological, and whatever cause operated in that case could have operated in others. Another is that the sound-change posited to explain /r/-less pronouns in WG is, according to Hogg and Fulk (2011, 198), "exceptional", i.e. not regular. Indeed it is not entirely clear that the occurrence of "/r/-less" pronouns in N-WG and "/r/-full" pronouns in S-WG has a unitary explanation: nominatives with or without /r/ could be due to leveling in diff erent directions, and datives without /r/ could be due to replacement by the accusative. Though Hogg and Fulk (2011, 203) regard endingless accusatives in OE as datives employed as accusatives, this does not tell us much if the origin of these is not clear, and it is quite possible that the forms in question are actually accusatives employed as datives.
A complication is that Anglian OE and OS, both from the NE part of the N-WG area, show distinct accusatives with an ending pointing back to original /-k/, though these are always in competition with endingless accusatives (Campbell 1959, 288;Rauch 1992, xxx). Since in Gothic and Norse only "endingful" accusatives with /-k/ occur (Wright [1910(Wright [ ]1954Gordon [1927Gordon [ ]1957, it seems clear that endingless accusatives in N-WG are the result of an innovation that originated along the more westerly coast of the North Sea, in eff ect taking a bite out of the much larger area that retained accusative /-k/. The innovation was thus marginal rather than central, which is somewhat odd. Its geography, even considered in isolation, would suggest external motivation. But its geography does not exist in isolation. Endingless accusatives in Germanic are integrally associated with loss of the accusative/dative distinction, which also occurs in neighboring Old French. Thus we have some reason to suspect that endlingless accusatives in N-WG are the result of an externally motivated innovation connected in one way or another with similar developments in Old French. There is a simple rule, valid for both Old French and N-WG, as to what pronouns lose the accusative/dative distinction: every personal pronoun that either may or must have refl exive meaning loses the accusative/dative distinction. Only Old French shows the syndrome applying to all possible instances: /me, te, se/. These are most simply seen as accusatives employed as both accusatives and datives, as is indisputably the case with /nos, vos/ (Mendeloff 1969, 62). Thus at least for Old French it is clear that its common accusative/datives are accusatives employed as datives. As for N-WG, if we ignore for the moment distinct accusatives existing alongside non-distinct accusatives, the situation is the same as in Old French, except for the predictable absence of refl exives in OE and (original) OD and OS. The common accusative/dative forms seen in N-WG can be regarded as endingless accusatives employed as datives. Doing so permits a unifi ed description of the overall evidence: loss of the always-refl exive 3 rd person dative with /s-/ (which occurs in Old French and all WG) is more widespread than loss of the sometimes-refl exive non-3 rd person datives without /s-/ (which occurs in Old French and N-WG). The point of a unifi ed description is that it might permit a unifi ed explanation. There appear to be two possibilities.
The fi rst possibility is that some cause created a greater motivation for loss of always-refl exive datives than for loss of sometimes-refl exive datives. For persons whose only native language was Celtic, the combination of dative refl exives and external possession would have been doubly diffi cult, given that both concepts were alien to Celtic. Latin /sibi/ and WG /siz/ must have been used very often in ways that were diffi cult for the Celtic mind to comprehend. Infl uences from Celtic, temporarily stronger than they later became, may well have much to do with why external possession, though it occurs in both Classical Latin and later Romance, is oddly absent in Late Latin (Luraghi, f.c.). It is worth noting that when dative refl exives are revived in French and German, the form employed is the accusative, which is to say that the dative has already been lost. With non-3 rd pronouns, which were only sometimes refl exive, the impetus toward loss would have been weaker. But though this would explain why loss of the dative refl exive occurs more widely than loss of other datives, it would not explain why loss of non-3 rd datives occurs where it does: the area of Old French and N-WG.
The second possibility begins with the observation that odd parallels between Old French and Old English must be suspected of being due to parallel Celtic substratal infl uences "under" French and English. A good example is the odd palatalization and vocalization of /k/ before /t/ seen in English "night" and French "nuit", compared with Welsh "noeth" (and contrasted with German and Dutch "nacht"). In Celtic, forms pointing back to /me, te/, though clearly accusatives in origin, were employed as common accusative/datives (Lewis andPedersen [1961]1989, 194-195, 204-205). Thus Celtic /me, te/ might well be identifi ed with Latin/Romance /me, te/ and (less straightforwardly) with Germanic /mek, Өek/ by equivalence interference. The Germanic half of this makes more sense when we consider that the spread of Germanic into the area of NW continental WG evidently occurred early enough to pre-date Grimm's Law, so that what Celts encountered in Germanic was /mek, tek/. There are two reasons that getting rid of /-k/ would seem sensible to Celts: 1) /-k/ did not correspond to any element in Celtic, and 2) /-k/ did not make any distinction that Celtic made (in its non-3 rd pronouns). This scenario, unlike the one given just above, would explain why loss of non-3 rd datives occurs where it does: there is (as has been seen) independent evidence suggesting that Celtic infl uences were stronger in N-WG (and Old French) than in S-WG. The similarity between /me(e), Ѳe(e)/ in Old English and /me, te/ in Old French is almost certainly not coincidental.
It seems most probable that the fi rst possibility lies behind the widespread loss of the dative refl exive pronoun, and that the second possibility lies behind the more limited use of endingless accusatives as common accusative/datives in non-3 rd pronouns.
The further development, and unexpected demise, of accusative /-c/ in OE remains to be treated. In Anglian OE (the only kind of OE where they occur), accusatives with /-c/ are always (as has been seen) in competition with endingless accusatives identical with the dative. They had evidently become archaic/poetic variants, and do not survive the transition to post-AS English (Mossé,. 7 As this violates the general rule that Anglian variants dominate in Middle English, some explanation is required. Here it must be relevant that N-WG in Britain was subjected to another round of Celtic substratal infl uence simply by being in Britain. Even if by this time earlier /me, te/ had been reduced to something like /m, Ѳ/, the same general considerations would apply: /m, Ѳ/ would be recognizably cognate with OE /me(c), Ѳe(c)/, both were common accusative/datives, and accusative /-c/ would seem pointless. But since apocope in Brittonic did not, apparently, happen till around 525 (Jackson 1953, 695-696), chances are that what happened in Britain during the early AS conquest in the N was a repeat of what had happened earlier on the continent, leaving accusative /-c/ mortally wounded even where it had been strong.

Conclusion
The fact that Celtic had neither refl exives nor external possession had very signifi cant consequences for WG, both southerly and northerly, not to mention for Old French (and other Romance). In all three, the refl exive/non-refl exive distinction in genitive/possessives and the dative of the refl exive were lost. In all of WG, an abortive attempt to save the refl exive/non-refl exive distinction in Fs, by using the D-SG as an indirect refl exive, led to "dative intrusion" in the G-SG in F thematics. In N-WG, stronger infl uences from Celtic led to the refl exive/ non-refl exive distinction being entirely lost. In westerly N-WG and Old French, Celtic infl uence caused the accusative (in WG shorn of its /-k/) to replace the dative. In English, another round of Celtic infl uence caused the same process to happen again, so that Anglian forms with /-c/ were lost. The developments seen in WG and Old French cannot be considered in isolation from each other, and neither can be understood without reference to Celtic substratal infl uence.

N/A-PL /-ͻͻs/ in Northerly WG
It has never been explained why N-WG shows /-s/ in the N/A-PL of M /a/-stems. And it has always been ignored that N-WG, as it spread SW into territory formerly belonging to other forms of IE, re-developed a plural ending that was widespread in older IE. If we set aside for a moment the evidence of WG, which is the disputed case, it is clear that the N-PL of M thematics should have become /-ͻͻz/, from late PIE /-oos/ < /-oes/. The N-PL and A-PL of F thematics (along with the G-SG) should have become /-ͻͻz/, in this case from late PIE /-aas/. (Reasons to think that the expected third vocalic mora was somehow lost, due to early development of /aa/, were given in the section 3.1.) As with the G-SG of F thematics, non-WG retains the expected syncretisms unaltered except by regular sound-change, Gothic with /-oos/ and Norse with /-ar/ (Wright [1910(Wright [ ]1954Gordon [1927Gordon [ ]1957, and the question is why N-WG does not do the same. Developments are complicated by the fact that the N/A distinction in PLs was, except for a few archaisms in the F thematics of EWS (Campbell 1959, 234), completely lost in WG (Prokosch 1939, 241, 244;Cowan 1961, 36;Bremmer 2009, 60, 62). Accordingly it is necessary before proceeding to reconstruct the situation in WG before this loss. The forms seen in WG point back to two Vs, one short (as in Anglian OE /-e/ < /-a/) and one long (as in non-Anglian OE /-a/ < /-oo/). Since 1) a short V would make more sense before /-nz/ than before /-z/, 2) the form with a short V occurs only as an accusative in EWS (Campbell 1959, 234), and 3) the evidence of non-WG shows that the form with a long V is older, it seems clear that a new F A-PL was created by simply throwing the M A-PL /-ͻnz/ into the breach. It is worth noting that the later falling together of N-PL and A-PL in WG may well be due to Celtic infl uences (later than those posited below), since thematic N-PL forms in Celtic were (before the M ending was replaced by a pronominal form) the same as A-PL forms: /-uus/ < /-oos/ in M thematics and /-aas/ in F thematics (Stifter 2006, 43, 59).
The reason that the origin of A-PL /-s/ remains an unsolved problem is that the proposals that have been made to date make little sense. Final stress would be ad hoc. Ringe and Taylor's idea (2014, 162-163) that /-s/ is not plural /-s/, but rather somehow the same element as /-s/ in PDE "this" and NHG "diese", just goes to show that desperate situations do indeed produce desperate expedients. Little better is the idea is that the forms seen go back to a double plural /-ͻͻs-ɛz/ (Hogg and Fulk 2011, 11-12). (The tri-moraic V posited by Hogg and Fulk, which is without morphological warrant, has above been replaced by a bi-moraic V of the normal kind.) But as Ringe and Taylor (2014, 116) note, a double plural is not independently evidenced, and would have no clear motivation.
Arguments in favor of /-ͻͻs-ɛz/ are wholly dependent on the plausibility of double plurals. But this leaves quite a lot to be desired. Though double plurals occur in Vedic and Avestan (Sihler 1995, 261), literally all of our evidence on these languages comes from poetry, where if a double plural fi t the meter a single plural would not. Such double plurals are almost certainly artifi cial creations motivated by metrics. Furthermore, double plurals in Vedic represent only about 1/3 of such forms, so that it is not as if double plurals have actually replaced single plurals, which is what is posited for WG. The one double plural from outside of Indo-Iranian that Sihler (1995, 261) cites, "herring boxes without topses" from "Clementine", is also from poetry, and occurs in a situation where a single plural would spoil the meter (and the rhyme). In Dutch cases like "tenen" 'toes', medial /n/ was long ago reinterpreted as belonging to the SG (Donaldson 1983, 164-165). If no better examples than these can be brought forth, there is no good reason to believe that double plurals are a naturally occurring innovation in human language.
Though it is traditional to posit that the change of /-z/ to /-s/ occurred in N-PL /-ͻͻz/, there is no compelling reason to do so, and it also works, as is rather casually suggested by Ellis (1966, 29), to posit that /-s/ developed in A-PL /-ͻnz/. New /-ͻns/ would regularly become /-ͻͻs/, later appearing as /-as/ in OE and as /-os/ in OS. 8 The obvious question is why it would strike anyone as a good idea to change /-ͻnz/ to /-ͻns/. A diff erent version of the same question, no easier to answer, is not avoided by going back to the idea that the change was really /-ͻͻz/ to /-ͻͻs/. As a century or two of futility has shown, there is no reason that changing /-ͻnz/ to /-ͻns/ would seem like a good idea to native speakers of Germanic.
The only remaining possibility, of course, is that it seemed like a good idea to non-native speakers of Germanic. As has been noted, the development of plural /-s/ in N-WG created an areal resemblance to other IE languages with plural /-s/. Though the fact that N-WG winds up patterning with Latin/Romance and Celtic in having plurals with /-s/ has long been implicitly dismissed as merely coincidental, we have just seen reasons to doubt that. The linguistics of this case will work only if the requisite non-native speakers were speakers of an IE language that had A-PLs in /-ns/, but not in /-nz/. Though Latin/Romance does not qualify in this regard, Celtic does. According to Stifter (2006, 43, 59), there was a time when Celtic had /-ons/ in the A-PL of M thematics but /-aas/ in the F-PL of F thematics. It also had /-ans/ in C-stems (Stifter 2006, 47). The WG analogues of these would have been M thematic /-ͻnz/, F thematic /-ͻnz/, and C-stem /-unz/. Only in the case of M thematic /-ͻnz/ is there any close similarity between Celtic and Germanic. (In unstressed position before a nasal, the diff erence between Germanic /ͻ/ and Celtic /a/ would not prevent recognition of cognate morphology.) Thus "correction" of /-ͻnz/ to /-ͻns/ would have been motivated in M thematics, but not elsewhere. As the innovation in question seems to require external infl uences being rather strong, it would be more likely to occur in N-WG.
A good question is whether the scenario proposed might have some unwanted side-eff ects. In theory, alteration of /-nz/ to /-ns/ might also be expected with /i/-stems, /u/-stems, and C-stems (which had A-PL /-unz/) in Germanic, since Celtic had /-ins, -uns/ as the A-PL of /i, u/-stems. But in WG the A-PL forms of /i/-stems and /u/-stems could well go back to the N-PL (Ringe and Taylor 2014, 375;Hogg and Fulk 2011, 39, 48), so that there can be no decisive evidence on this point. The fact that Gothic /futu/ 'foot' and /tunӨu/ 'tooth' were transferred from the C-stems to the /u/-stems/ does indeed provide good evidence that C-stems once had A-PL /-unz/. But the widespread syncretism of A-PL and N-PL in Germanic must have had a starting point, and as the C-stems of older Germanic never show any contrast between A-PL and N-PL (Prokosch 1939, 249, 250, 257), it seems probable that the starting point was in C-stems. Though Ringe and Taylor (2014, 376) suggest that /-u/ in "bordwudu" (Beo 1243) is a distinct A-PL ending going back to /-unz/, it may well be an A-SG ending employed simply because (archaic) A-PL /-oo/ would spoil the meter. If so, the correct literal translation of the phrase is not "bright board-woods" but rather "bright board-wood". The bottom line is that there do not appear to be any unwanted side-eff ects.
To sum up, what happened was apparently as follows. As the ancestor of N-WG spread to the SW and was thus imposed on speakers of Celtic, A-PL /-ͻnz/ in the M thematics of WG was identifi ed with A-PL /-ons/ in the M thematics of Celtic. To the Celtic mind, /-z/ (which did not exist in Celtic) appeared to be wrong, and so was corrected to /-s/. To say that it is predictable that Celtic infl uence would cause /-nz/ to become /-ns/ would be getting carried away. But it is at least understandable. Since otherwise we have no plausible explanation for why the change of /-z/ to /-s/ happened at all, much less why it happened in WG only and in M thematics only, it seems best to posit that this is indeed what happened.
It would be remiss not to note that the general loss of /z/ in WG, both after Vs and after /n/ (whether or not /z/ in /nz/ was in N-WG lost by becoming /s/) could be due to the absence of /z/ (and presence of /s/) in Celtic. But to posit that /z/ in /-nz/ was, just randomly, altered to /-s/ in N-WG but lost in S-WG, implying that any of the three other possible outcomes was just as probable, is both unattractive and unnecessary. Development of A-PL /-ͻns/ in N-WG seems better seen as motivated by the existence of A-PL /-ons/ in Celtic, in an area where there is independent evidence that Celtic infl uences were stronger than in S-WG.

The Gerund and the Present Participle with /-(i)yͻ-/ in West Germanic
It is a noted peculiarity of WG that its verbal nouns, instead of being limited to an infi nitive with only a N/A form, as in other Germanic, developed (at least in theory) the full range of cases, and that these are based not on the old stem /-ͻ-/ but rather on a new stem /-yͻ-/ (Ringe and Taylor 2014, 79). Ringe and Taylor do not suggest a motivation for either aspect of this innovation. But Celtic infl uence can certainly explain the fi rst half of this innovation and may well explain the second as well. Celtic is locally notorious for having verbal nouns that are very "nouny" in being normal abstract nouns, with no limitation on case (Lewis andPedersen [1961]1989, 312). The development of "extra" cases in WG is thus quite plausibly seen as due to Celtic infl uence.
The same is quite probably true of what appears to be randomly intruded /y/ in /-yͻ-/. But this case is quite a lot more complex. First off , it may be noted that present participles in WG also developed /-y/ (Ringe and Taylor 2014, 78), automatically converted to /-iyͻ/ by Sievers' Law, which in eff ect prevented contrast between /y/ and /i(y)/ in many circumstances. For presentational convenience, both will (arbitrarily) be referred to as /y/ from here on. It must arouse some suspicion that unexpected /y/ develops in both present participles and gerunds. That some connection between the two was felt is demonstrated by the fact that present participles often do not show umlaut, apparently on the model of infi nitives (Ringe and Taylor 2014, 78). If, as posited above (section 2), Germanic infi nitives once had /-nt/, similarity of sound might be part of the answer. But whatever eff ects followed from similarity of sound should have applied with equal force across all Germanic, so why do we see results only in WG?
We may suspect that, in this case as in some others treated above, the answer has something to do with Celtic. Though Celtic had verbal nouns with both /-yo-/ and /-o-/ (Thurneysen 1946, 448), there is no obvious reason that Celtic infl uence would cause /-ͻ-/ to be replaced by /-yͻ-/ in WG. But there is an un-obvious reason: it seems that in most forms of Gallo-Brittonic (all but Cornish/Breton) the inherited gerund became regarded as also a present participle. (The cause is basically that /in/ < /sind/ 'thus', which had been pressed into service as a predicate marker, was homophonous with /in/ 'in'.) Such identity occurs in English, Welsh, and (marginally) in French, in usages like "Il est parti en disent cela" ('He left saying that'). It was much more common (though evidently beginning to be restricted) in Old French, where one can fi nd things like "par mes armes portant" 'by carrying my weapons' (Kibler 1984, 284). Since these three languages are areally adjacent but not closely related, the usual reasoning applies: where unusual resemblances occur across language boundaries, the cause is language contact. In this case, as in others that have been seen above, the only historically plausible language contact is Celtic substratal infl uence, leading to parallel independent innovations in English and French.
Turning back now to WG, if the present participle in WG had already developed /-yͻ-/, to Celts it would seem that the gerund too ought to have /-yͻ-/. Though obviously the two did not fall together, substratal infl uences can be resisted or even reversed: we have already seen that in French this happened with the refl exive/ non-refl exive distinction. In WG, modeling the gerund on the present participle would have started with /-ͻnd-yͻ/ being employed in both the present participle and the gerund, followed by later re-formation as /-ͻn-yͻ/ after fi nal /-t/ was lost in the infi nitive.
As for why the distribution of forms with and without /y/ is as it is, with /y/ in extra case forms but not in the infi nitive, extra case forms and intrusive /y/ would at fi rst have been associated with Celtic-accented speech, so that they would become associated with each other. By contrast, the use of the inherited N/A form without /y/ would be characteristic of non-accented speech. The result would be extra cases in /-yͻ-/ opposed to the N/A in /-ͻn/.
It seems then that all three of the unexpected developments seen in WG, 1) creation of "extra" case forms for the infi nitive, 2) intrusion of /y/, and 3) the distribution of forms with and without /y/, can be explained as being due to Celtic substratal infl uence.

Generalization of /-ɑn/ in the /n/-stems of Anglo-Frisian
It must be stressed that this case is fundamentally diff erent from the ones that have been treated above, as it involves later Celtic infl uences limited to Anglo-Frisian (AF).
It is a peculiarity of AF that it has streamlined the declension of /n/-stems by always having /ɑ/ (> /a/ in F) before /n/ (Hogg and Fulk 2011, 53;Ringe and Taylor 2014, 163-164), except for some early archaisms and G-PL /-ena/, which is clearly secondary. Ringe and Taylor describe this development as "obscure" (as in having no clear explanation). The treatment given by Hogg and Fulk (2011, 52-54) seems to show embarrassed silence as to why AF does not show variations of the sort seen in all other Germanic languages textually attested before the year 1000. It seems that there was in AF a stronger motivation to regularize the paradigm of /n/-stems than existed in other Germanic. But the conventional wisdom says nothing about what that motivation was.
The diff erence between AF and other WG can be attributed to additional Celtic infl uences consequent upon N-WG spreading to Britain. 9 An obvious consideration is that secondary acquisition tends to promote regularization. But since Old English (unlike Middle English) does not in general show reduced morphology in comparison with other Germanic languages of its time, there must have been some additional factor that caused the /n/-stems to be singled out for special treatment. This is not hard to fi nd. According to Stifter (2006, 209), Celtic had (except in the decades of open-minded investigation. There is no equation we could plug numbers into to tell us how many years we have to wait before deciding that traditional methods no longer have much chance of solving classic problems. But it does seem probable that this point has been reached. Though there are a few cases where traditional methods have recently succeeded in solving problems, all of the cases in question are minor, and several major problems ("classic" or not) remain as unsolved as ever. If some innovations in Germanic were in fact externally motivated, which is hardly improbable, it is predictable that they would become unsolved problems. Logically speaking, the converse does not apply. But practically speaking, it is diffi cult to see why whatever satisfactory solutions that could be discovered using traditional methods have not already been discovered. Given traditional assumptions, the only two possibilities are 1) that many generations of Germanicists, knowledgeably and intelligently applying traditional methods, have failed to fi nd internal motivations that did in fact exist, or 2) that some innovations in Germanic occurred without having any motivation. As neither of these makes sense, the conclusion must be that at least some of the innovations of Germanic, quite probably including a few classic problems, had external motivations. The cases treated above are intended to provide some candidates.
Notes 1 A change of unstressed /ͻ/ to /u/ before nasals might allow preterit 3PL /-un/ to be derived from a (re-formed) perfect ending /-ͻnd/. It might also explain /hund/ < /hͻnd/ in numbers. The conditioning environment appears to be very weakly stressed syllables: fi nal or later than second.