Allomorphy in the Hittite common gender accusative plural

It has recently become generally accepted that Hittite possessed two non-low back vowel phonemes denoted by means of plene spelling with ⟨u⟩ and ⟨ú⟩, representing /o/ and /u/, respectively. Upon reviewing all available evidence of plene spelling in the Hittite common gender accusative plural ending it is observed that the choice of vowel sign alternates. This forces us to reckon with at least two allomorphs of the acc.pl.c. ending, -/us/ and -/os/, which in turn demand explanations. The choice of ending appears to be largely contingent on the stem type of the nominal to which it is attached, forming a complementary distribution. For example, ablauting u -stems take -/os/ and i -stems take -/us/. Building on this observation, a diachronic scenario is formulated to account for all observable ending allomorphy. It is argued that the endings of the non-ablauting i -stems and the barytone a -stems were analogically introduced. In the i -stems, the inherited ending -/us/ of the ablauting i -stems was generalised to all i -stems, whereas the source of the ending in the a -stems remains unknown. The sound laws resulting from this analysis indicate that the vocalic outcomes of final *-( V ) m # are symmetrical to those of *-( V ) ms #, leading to an improved economy in Hittite historical phonology.


Introduction
Throughout the history of Hittitology, it has been commonly assumed that Hittite possessed only one non-low back vowel phoneme: /u/.1 In recent years, however, it has become apparent that Hittite knew an additional phoneme /o/, separate from /u/, denoted by means of plene spelling with ⟨u⟩ rather than ⟨ú⟩ (Rieken 2005a;Kloekhorst 2008: 35-60).This is now commonly accepted in the field at large.2The fact that ⟨u⟩ and ⟨ú⟩ denoted different phonemes demands a reassessment of cases in which the signs alternate.One such case is the common gender accusative plural ending, traditionally given as -us.3This ending is most commonly spelled with a single VC-sign, i.e., -⟨uš⟩.In these cases, it is in principle not possible to know whether the ending is to be interpreted as Hitt.
-/us/ or -/os/, since the sign ⟨uš⟩ is underspecified with regard to vocalism in either /o/ or /u/.However, in a number of instances, the ending is spelled with a V-sign-either plene as -⟨V-uš⟩ or when preceding a vocalic enclitic as -⟨V-š=a⟩.In these cases, the choice of sign alternates between ⟨u⟩ and ⟨ú⟩, which justifies further inquiry into the phonological properties of the ending.This was undertaken by Melchert (2020: 269-272), who concluded that -/os/ is the only extant ending.In the following, the results of a further study into this matter are presented and discussed, leading to the separate conclusion that both -/os/ and -/us/ must be assumed for the acc.pl.c.Subsequently, a diachronic scenario is formulated to account for the distribution of these allomorphs.

Data
All possible acc.pl.c.forms from Hittite texts written with either ⟨u⟩ or ⟨ú⟩ that I have been able to locate are found in Table 1.4In the "Stem type" col-  (Kloekhorst 2008;Melchert 2020), as well as in an electronic corpus containing ca. 286,000 words from ca. 3,365 texts, originally compiled by Johann Tischler and expanded by H. Craig Melchert and Alwin Kloekhorst.All cited forms have been checked against the photographs in the Konkordanz der hethitischen Keilschrifttafeln (Košak 2002(Košak -2022)).I thank an anonymous reviewer for refinements concerning the dating of certain attestations.
billing Indo-European Linguistics 10 (2022) 3-32 umn the earliest known stem type of the corresponding lemma has been given.For example, ⟨šu-up-pí-ú-uš⟩ is accordingly given as an ablauting i-stem, even though the cited attestation is inflected as a non-ablauting stem, since the earliest attested stem had an ablauting paradigm (thus acc.pl.c.⟨šu-up-pa-uš⟩).5Enclitics are included when the border between ending and enclitic falls within the same sign.Items preceded by question marks are less certain and discussed in the individual sections when relevant.
In the case of ⟨a-ú-li-ú-uš⟩, which is always spelled with ⟨ú⟩, we find direct evidence that the vowel of the ending is /u/.On KUB 17.21 ii 18, the form is followed by enclitics and spelled ⟨a-ú-li-ú-š=a=kán⟩, which cannot represent anything but /ʔaulius=a=kan/.Note that the quality of the vowel in the spelling -⟨li-ú-š=a-⟩ is consistent with the one in the spelling -⟨li-ú-uš⟩.Thus, we may infer that spellings of the type -⟨Ci-ú-uš⟩ denote a phonological sequence -/ius/.Additional comparable cases with unambiguous acc.pl.c.endings in -/us/ include ⟨ḫa-an-te-ez-zi-ú-š=a⟩ and ⟨ḫa-a-ri-ú-š=a=w[a=kán]⟩, both nonablauting i-stems.Irrespective of whether the ⟨ú⟩ in a spelling like ⟨a-ú-li-ú-uš⟩ denotes a glide [w] or some sort of hiatus, it is evident that the choice of plene spelling V-sign in this case corresponds to the vocalic quality of the ending.8 The argument put forward above for interpreting spellings of the type ⟨Ciú-uš⟩ as representing -/ius/ is likewise valid for interpreting spellings like -⟨Ca-ú-uš⟩ as -/aus/, i.e., the acc.pl.c. of the ablauting i-stems.Note the pair ⟨(NINDA)ḫar-ša-ú-uš⟩ and ⟨NINDAḫar-ša-ú-š=a⟩ with a following enclitic, completely analogous to the case of ⟨a-ú-li-ú-uš⟩ vs. ⟨a-ú-li-ú-š=a=kán⟩ provided in the previous paragraph.To this example the form ⟨ḫa-tu-ga-ú-š=a⟩ may be added, which likewise belongs to an ablauting i-stem.It is thus clear that spellings like -⟨Ca-ú-uš⟩ represent a phonological sequence -/Caus/ in the of the present paper is the vocalic quality of the ending.See also Section 4.3 for the possible marginal and archaic allomorph -/as/.8 An anonymous reviewer remarks that the pair ⟨a-ú-li-ú-š=a=kán⟩ and ⟨a-ú-li-ú-uš⟩ cannot reveal the vocalism of the ending, attributing the choice of V-sign to "graphic shortening".As a parallel in the nom.pl.c., the pair ⟨ḫa-a-pí-e-eš⟩ and ⟨ḫa-a-pí-e-š=a⟩ is adduced, where the signs preceding ⟨eš⟩/⟨ša⟩ are identical in both forms.To my mind, this is not a coherent argument against interpreting ⟨a-ú-li-ú-š=a=kán⟩ as a phonologically motivated spelling.In the spelling ⟨ḫa-a-pí-e-š=a⟩, there is to my knowledge no controversy as to whether or not the ending vowel is /e/.The same should hold for ⟨a-ú-li-ú-š=a=kán⟩, where quality of the vowel is determinable as /u/ by the same logic.
We may conclude that plene spellings for the acc.pl.c.ending indicate the phonemic vowel quality of the ending, barring obvious cases of misspelling.We may thus proceed with analysing the distribution of the endings.

Distribution
Given that the acc.pl.c.endings are spelled with both ⟨u⟩ and ⟨ú⟩ in the Hittite corpus, we must contend with the fact that the ending has (at least) two allomorphs: -/us/ and -/os/.15It follows that an attempt at establishing a distribution is possible.Kloekhorst (2008: 56-57) also recognises two acc.pl.c.allomorphs, -/us/ and -/os/, in Hittite (in his view rather -/ųs/ and -/ǫs/), postulating a chronological distribution.Under his analysis, PIE *-m̥ s# and *-oms# yielded OH -/ųs/, which in NH regularly became -/ǫs/.This scenario is not compatible with the data, however.16First, the form ⟨a-ku-u-uš⟩ has /o/-quality despite being no explicit stance is taken on the validity of this proposal, the /a/ is rendered short in this article in order to avoid potential confusion.14 Cf. ⟨e-ep-pu-u-un⟩ 'I seized' (e.g., KUB 1.2 ii 15; NH/NS), where the ending can hardly be accented and/or long (Kloekhorst 2014: 520-522).15 Cf. n. 7 for the possible additional allomorph -/óːs/ and Section 4.3 for the marginal -/as/.16 Kloekhorst concedes that the form ⟨[i-da-a]-⸢la⸣-mu-u?-š=a⟩ is problematic on account of its early attestation (KBo 15.10 iii 54; OH/MS).This counterexample may not be conclusive by itself, however.Upon reviewing the 3D model of the tablet available at the Konkordanz (Košak 2002(Košak -2022)), it is not clear whether the Winkelhaken constituting a supposed ⟨u⟩ is a separate sign or an exaggerated imprint of one of the four Winkelhaken in the sign ⟨mu⟩.Hence, the form is given with a question mark in Tables 1 and 2. attested in an OS text.17Moreover, disregarding palaeographical tiers, both endings occur in compositions from all Hittite chronological layers.To illustrate, in OH/NS texts we find both ⟨pár-ga-u-uš⟩ and ⟨ḫa-tu-ga-ú-š=a⟩, etc.A chronological distribution of the endings -/us/ and -/os/ is thus difficult to maintain.Upon reviewing the forms in Table 1, one particular pattern emerges.The choice of vowel sign, and consequently ending allomorph, seems mainly contingent on the earliest attested stem type of the nominal to which the ending is attached.The endings -/us/ and -/os/ thus occur in a largely morphologically conditioned complementary distribution.All i-stems, irrespective of whether ablauting or non-ablauting, take -/us/ as their acc.pl.c.ending (see Section 4.1 for ⟨l[i-in]-ga-u!-uš⟩).Conversely, the demonstrative pronouns show /o/vocalism, as do original u-stems (the word for 'four' is dubious, see Section 4.2).The a-stems and the original n-stem ⟨ku-ut-ru-u-uš⟩ take /u/ and /o/-endings respectively, although the following sections will cast doubt on their probative value.The only real exception to the distribution is the word for 'rain' , treated separately in Section 5.
With a complementary distribution established, we can move on to determining the etymological sources of the endings.

4
The development of -/us/ and -/os/ Since we have established that the choice of ending is contingent on original stem type, we may now use this to determine the etymologies of -/us/ and -/o(ː)s/.The first question is whether the realisation that Hittite had several allomorphs for the acc.pl.c.ending gives us reason to modify the acc.pl.ending *-(o)ms as traditionally reconstructed and well-established in Indo-European linguistics.18Since projecting the allomorphy back in time would entail multiplying entities (in this case morphemes) in the proto-language, it should only be considered if forced, i.e., if we can find no other plausible explanatory scenario specific to Hittite.In the following, it will be argued that such a scenario is possible.There is consequently no need to modify the tradi-17 The pronouns ⟨a-pu-u-uš⟩ and ⟨ku-u-uš⟩ are unproblematic for Kloekhorst even though these are abundantly attested from OS onwards, since they are special cases reflecting *-óms# (see Section 4.1).Moreover, Kloekhorst (2008: 168) doubts the validity of the form ⟨a-ku-u-uš⟩ as it occurs in a rather fragmentary context.Here, it is taken as real, following Puhvel (1984: 24).18 As is commonplace, I reconstruct the ending with *m rather than *n on the basis of internal reconstruction (see Meier-Brügger 2003: 196;Kim 2012: 146 with further references).
tional reconstructions.Accordingly, we may in principle postulate either *-ms (for athematic stems) or *-oms (for thematic stems, accented or unaccented) as input sequences for the attested forms.19
According to Melchert (2020: 270), acc.pl.c.⟨a-ku-u-uš⟩ 'sea shell' (OS) indicates that *-Cums# yielded Hitt.-/os/.This is argued on the premise that the word is an original non-ablauting u-stem, as indicated by the nom.sg.and acc.sg.forms ⟨a-ku-uš⟩ (KUB 21.19+ iii 14; NH/NS) and ⟨a-ku-un⟩ (KUB 36.12 ii 6; OH/NS), respectively.However, while possible, this is not necessarily the case.The traditional connection to the PIE root *h2eḱ-(cf.Skt.áśman-, Gk. ἄκμων, Lith.akmuõ 'stone') with u-stem formation (cf.Lat.acus) made by Laroche (1957: 25-26) based on the outdated translation as 'stone' should be abandoned on semantic grounds (aku-rather meant 'sea shell'; see Hoffner 1978: 245).Consequently, we cannot exclude the possibility of an original root noun ending in a labiovelar.In that case, -/os/ would go back to a sequence *-Cm̥ s#.We must conclude that ⟨a-ku-u-uš⟩ is not absolute in determining the outcome of *-Cums#, although -/Cos/ is not unlikely per se.A PA input sequence *-gʷm̥ s# could also have given rise to this item.25 ga-u!-uš⟩ 'oaths' .However, this form is not assigned any probative value in this paper (see main text, this section).This modelling of ablauting u-stems on an ai-stem is in either case hardly likely, especially given the consistent use of -/us/ in the i-stems (see Section 4.2).24 The labial glide present in the weak stem forms of these words is also often spelled with ⟨u⟩.In intervocalic position, however, the choice of sign is not phonologically contrastive (Hart 1983: 124-128;Kloekhorst 2008: 40-42).Moreover, ⟨ú⟩ does in fact also occur spelling this glide, e.g., ⟨i-ta-a-la-⸢ú⸣-i⟩ (KBo 25.103 rev.3; OS), ⟨a-aš-ša-ú-e-et⟩ (KBo 8.69, 10; OH/NS).Note also that ⟨u⟩ requires fewer wedges than ⟨ú⟩, which may partly motivate its more frequent use in this position (while also incidentally increasing the probative value of the consistent use of ⟨ú⟩ in the i-stem acc.pl.c.).25 If the word ⟨NA4a-ku-wa-an-du-uš⟩ 'covered with sea shells' (KUB 35.84 ii 4; NS, used to describe roads) is a possessive derivative in -want-(thus in Kronasser 1966: 266), a u-stem would be impossible, since we would then expect a form **akumant-by sound law.A u-stem would consequently necessitate a derivative in -ant-(thus in Hoffner & Melchert 2008: 56).However, the formation naduwant-'having reeds' (used for ponds and meadows; see Puhvel 2007: 66) from (GI)nāta(/i)-'reed' has an at least superficially similar function of describing a certain terrain "possessing" the object denoted by the derivational base (see Steer 2012 for a comprehensive discussion on the word both synchronically and diachronically).This might point to a akuwant being a stem in -want-, and thus to aku-ending in a labiovelar, phonologically /ʔakʷ-/, being the more likely situation, in which case ⟨aku-u-uš⟩ /ʔakʷos/ would be tentative evidence of the development *-Cm̥ s# > -/Cos/.The parallel with naduwant-may be somewhat weakened by perunant-'rocky' , which could conceivably be argued to have a similar function.This word unambiguously displays the suffix -ant-, although it is less clear for perunant-whether the adjective describes the "possession" of a certain object by the landscape, in this case mountains, or the shape of the landscape itself (see Puhvel 2013: 25 for context).
The a-stems for which we have plene spelled acc.pl.c.endings are ⟨al-puú-uš⟩ 'cloud' , ⟨MUNUS.MEŠkat-ru-ú-uš⟩ '(female) functionary' , and ⟨mi-e-ú-uš⟩ 'four' , displaying ending vocalism in /u/.28There are indications that the first two of these are oxytone, whence the plene spelling of their endings is unsurprising.For 'cloud' , we have the nom.sg.form ⟨al-pa-a-aš⟩ (KUB 59.54 obv.7; LNS) and for '(female) functionary' we have the nom.pl.⟨[M]UNUS.MEŠkat-re-26 Already Sturtevant (1951: 90) derived the acc.pl.c.ending -us from a sequence *-Cm̥ s#, but before the difference between /u/ and /o/ was discovered.27 Note that this means that the acc.sg.c. of C-stems must have had a primary ending *-/on/ replaced by the ending of barytone a-stems, i.e., -/an/.This is hardly a problematic notion-see Melchert 1994: 181 with further references and see n. 21 for a possible similar substitution.28 The form ⟨ḫa-an-te-ez-zi-ú=ša⟩ should probably be included as evidence of the ending -/us/ being standard in the non-ablauting i-stems, even though it is an original a-stem, since it inflects as an i-stem at the time of its attestation (Melchert apud Kloekhorst 2008: 264).
For alpā-, the sometimes postulated connection to, e.g., Lat.albus 'white' is not unproblematic-the Hittite word does not denote white clouds, but rather rain-clouds (Puhvel 1984: 38), and the initial vocalism is difficult to reconcile with an initial #a-in Latin.29The insecurity concerning reconstruction ren-29 PIE *h2elbʰo-would have given Hitt.**halpa-.The word is sometimes reconstructed with Indo-European Linguistics 10 (2022) 3-32 ders the word unsuitable for postulating sound laws.Additional doubt is cast on the probative value of ⟨al-pu-ú-uš⟩ by an anonymous reviewer, who suggests analysing the form as the nom.sg.c. of alpu-'pointed' , with the resulting noun phrase ⟨al-pu-ú-uš ḫé-e-uš⟩ meaning 'lashing rain' rather than 'stormclouds (and) rains' (contra the reading in García Trabazo 2002: 264-265).In ⟨MUNUS.MEŠkat-ru-ú?-uš⟩, the sign ⟨ú⟩ is impressed on the edge of the tablet and is difficult to read in the picture uploaded to the Konkordanz (Košak 2002(Košak -2022)).An alternative reading with ⟨ru⟩ instead of ⟨ú⟩ is perhaps preferable, especially in comparison to the shape of the immediately preceding ⟨ru⟩ (cf.also the ⟨ú⟩ on line 4 with longer horizontals).30If this is the case, the form is misspelled and thus of low probative value.Moreover, even if the form is spelled correctly, nothing precludes an original stem in *-eh2-, for which the expected outcome of the acc.pl.c. in *-eh2-ms# would hardly be -/us/ (see Section 4.3).Since katrā-refers to an animate individual, the *eh2-inflection could be attributed to the individualising function of this suffix observed elsewhere in Anatolian (Hajnal 1994: 152;Melchert 2014;Sasseville 2018: 313-314).31In summary, ⟨al-pu-ú-uš⟩ and ⟨MUNUS.MEŠkat-ru-ú?-uš⟩and their apparent /u/vocalism hold little probative value.The type of stem underlying ⟨mi-e-ú-uš⟩ is not evident.It is often assumed to be a u-stem (Weitenberg 1984: 43) with some pronominally inflected forms (dat/loc.pl.⟨4-ta-aš⟩).However, an a-stem is also possible (favoured by the Luwic evidence per Sasseville in eDiAna-ID 1440 and suggested already in Weitenberg 1972: 41-42).If it is a u-stem, the apparent ending -/us/ is deviant (cf.Section 4.1) and the form could potentially be understood in the same way as the formally similar ⟨ḫé-e-ú-uš⟩ (see Section 5).In either case, the dubious stem assignment renders the probative value of the form unclear pending further evidence.
For the non-ablauting i-stems, it is unlikely that the ending -/us/ is primary.In a position *-Cims# the nasal would hardly vocalise and yield a back vowel; cf. the CLuw.acc.pl.c.ending of the i-mutating class -inz (Lyc.A -is) going back to an i-stem paradigm with zero-grade in the suffix (i.e., *-Cims#).32With the Luwic comparanda in mind, the expected outcome of a sequence *-Cims# is PIE radical vocalism in *a (see, e.g., Weiss 2020: 45)-a contentious issue that cannot be elaborated upon here (but see Pronk 2019 for the most recent critical account).A reconstruction with initial o-grade is theoretically conceivable if one assumes loss of initial laryngeals before *o (thus in Beekes 2010: 77-78).30 I thank an anonymous reviewer for this suggestion.31 Puhvel (1997: 137) expresses doubt that katrā-is an inherited word in the first place.32 Following the historical explanation of the i-mutating class by Norbruis (2018) pace Rieken (2005b).
billing Indo-European Linguistics 10 (2022) 3-32 rather Hitt.-/Cis/.Accordingly, the ending -/us/ must have been analogically introduced to the non-ablauting i-stems from some other class.Since an ending -/is/ would render the acc.pl.c.homonymic to the nom.sg.c., analogical introduction of -/us/ finds a clear motivation in distinguishing the acc.pl.c.from the nom.sg.c.
In the ablauting i-stems, we consistently find -/us/.According to what we know of Hittite historical morphology, these forms supposedly continue a desinential Pre-Hittite sequence *-ai̯ -m̥ s#.However, informed chiefly by the development of the ablauting u-stems (Section 4.1), we would rather expect -/os/ as the reflex of *-m̥ s#.Accordingly, the ending -/us/ in these forms must either have been analogically introduced, or we must modify the sound law to yield a different outcome when *-m̥ s# is preceded by *-i̯ -.In the following, it will be argued that circumstantial evidence favours the latter solution.
It has been observed in the previous section that the vocalic outcomes of word final sequences in *-ms# are identical to those for words ending in *-m#.By extension, we could hypothesise that this holds in the present case as well.Notably, the 1sg.pret.act. of the verb pai̯ i-mi 'to go' is attested as ⟨pa-a-ú-un⟩ in MS (KBo 16.59 rev.5) representing /páːun/.In later texts, this word is changed to ⟨pa-a-u-un⟩ (e.g., KUB 1.1 ii 23; NH/NS), indicating /páːon/.Kloekhorst (2008: 42-44) argues for a regular shift MH /aun/ > NH /aon/ to account for this development.However, the evidence for this sound law is not compelling (cf.Weeden 2011a: 68-69).Moreover, the evidence for word final MH /aun/# > NH /aon/# consists only of the item under discussion and is complicated by the acc.sg.c.form ⟨ḫar-na-ú-un⟩ 'birth-chair' (ABoT 1.17 ii 9; MH/NS).The disambiguating plene spelling in the 1sg.pret.act.form ⟨e-ep-pu-u-un⟩ /ʔépːon/ 'I seized' (e.g., KUB 1.2 ii 15; NH/NS) suggests that the regular outcome of *-Cm̥ # was Hitt.-/Con/.33It is therefore more attractive to assume analogy of /páːun/ >> /páːon/ to the regular 1sg.pret.act.ending -/on/.34In either case, it is clear 33 The spelling ⟨e-ep-pu-u-un⟩ only occurs in NH.Kloekhorst (2008: 54) argues for a sound change OH /un/ > NH /on/, but the evidence here is likewise hardly conclusive and I know of no other example of this development in word final position.34 Note that both ⟨pa-a-u-un⟩ and ⟨e-ep-pu-u-un⟩ occur in the same manuscript of CTH 81 ("The Apology of Hattusili").Melchert (2020: 268-269) argues that the spelling ⟨e-ep-puu-un⟩ is modelled on ⟨pa-a-u-un⟩, both showing a regular reflex -/on/ < *-m̥ # (Melchert does not regard MH ⟨pa-a-ú-un⟩ as probative; see the beginning of Section 2.2).The first claim is reasonable and provides a plausible motivation beyond disambiguation for the plene spelling in ⟨e-ep-pu-u-un⟩.Conversely, the second claim that ⟨pa-a-u-un⟩ has a directly inherited ending in -/on/ stands in contradiction to the argument put forward here.Note, however, that the spelling ⟨e-ep-pu-u-un⟩ being modelled on that of ⟨pa-a-that Pre-Hitt.*pā í̯ m̥ (< virtual *h1pói-h1(e)i-m) gave MH /páːun/.The evidence thus suggests the same vocalic outcome in /u/ from *-i̯ m̥ s# and *-i̯ m̥ #, separate from the outcomes in /o/ for *-Cm̥ s# and *-Cm̥ # determined in the previous section.Differential treatment is phonetically justifiable-raising of a vowel following the palatal *-i̯ -with its associated raising of the tongue is unsurprising; cf. the Luwic sound law *i̯ e > *i̯ i (Melchert 1994: 262 & 311).35

4.3
The acc.pl.c.ending of the barytone a-stems We are now left with one important stem class unaccounted for: the barytone a-stems.It is unfortunate that we have no securely probative plene spellings of acc.pl.c.endings for this type-they are virtually always spelled with a single ambiguous sign -⟨uš⟩.36This is hardly surprising, however, since the ending was never accented nor long and a Hittite speaker would have had no problem knowing which allomorph was grammatical.
The input stems for the barytone a-stem class are the *o-stems and the *eh2stems.For the original *eh2-stems, the ending -us (either -/us/ or -/os/) cannot be primary-an input sequence *-eh2-ms# would hardly yield either -/us/ or -/os/.37Regarding the original *o-stems, one could attempt to trace the ending -us directly to *-oms#.However, there are reasons to doubt that this is correct.38A strong parallelism has been observed between the outcome of sequences with a word-final *m to those with a final *m + *s.Following this parallelism, we u-un⟩ does not imply that the ending -/on/ is primary in ⟨pa-a-u-un⟩, only that the form was /páːon/ at the time of writing, i.e., post-analogy in the scenario argued for here.

35
I thank an anonymous reviewer for this suggestion.36 The possible a-stems ⟨mi-e-ú-uš⟩ and ⟨mi-ni-u-uš⟩ are argued to have low probative value in the preceding sections.It is most unlikely that both are a-stems, given that they suggest separate ending vocalisms.It is also possible that neither is an a-stem, in which case ⟨mi-e-ú-uš⟩ reflects a late shift of a u-stem to using -⟨ú-uš⟩ (cf.Section 5 on hēu-), while ⟨mi-ni-u-uš⟩ could be understood as a spelling error.The arguably more likely situation is that ⟨mi-ni-u-uš⟩ reflects a genuine a-stem, indicating -/os/, since this would avoid spelling error as an explanation and since ⟨ú⟩-spelling in ⟨mi-e-ú-uš⟩ as a u-stem is comparable to ⟨ḫé-e-ú-uš⟩.In either case, however, neither example is probative enough to determine the regular ending of the barytone a-stems with any certainty.For ⟨ḫa-an-teez-zi-ú=ša⟩, cf.n. 28.37 The expected output of *-eh2-ms# would probably be -/as/, displaying "extended" (i.e., laryngeal-affecting) Stang's law-like treatment of the laryngeal (Stang 1970: 43); cf.*duéh₂m > /twān/ 'hither, thither' (Melchert 1984: 30).The attested ending -us is thus in all likelihood secondary.On the issue of Stang's law, the laryngeals cannot be trivially equated with the resonants (cf.Byrd 2015: 141-142;Pronk 2016) and the law as it pertains to resonants still remains dubious in Anatolian (cf.n. 22 and Lyd.ciwν 'god' acc.sg.< *diéum).38 Melchert (2020: 271) likewise strongly doubts the validity of the ad hoc sound law *-oms# > Hitt.-/us/.
billing Indo-European Linguistics 10 (2022) 3-32 may entertain the notion that *-oms# would give Hitt.-/as/.39Note that the outcome of unaccented PIE *-ōn-s# is -/as/ (through PA *-ons# with a short vowel; see Melchert 1994: 76), e.g., Hitt.⟨ha-a-ra-aš⟩ 'eagle' < PIE *h3ér-ōn-s.Following Melchert (2020: 271-272), there is potentially positive evidence that the regular outcome of *-oms# is Hitt.-/as/.The word NINDAwagātas-'piece of bread (vel sim.)' is often analysed as a primary s-stem (Neu 1983: 208;Rieken 1999: 196-197;Kloekhorst 2008: 940), which in later Hittite becomes a common gender a-stem wagāta-; cf.acc.sg.⟨NINDAwa-ga-ta-an⟩ (KUB 10.28 i 12; OH/NS).40It is also generally connected to the verb wāk-hi/wakk-'to bite' .The reason for postulating an original s-stem comes from a number of OS attestations where a form ⟨wa-ga(-a)-t/da-aš⟩ is the direct object of the clause, always preceded by numbers higher than one.41However, an original s-stem is deeply problematic.First of all, as pointed out by Melchert, a collective formation wagāta (see Rieken 1999: 197 for attestations) is highly unlikely to be a recent creation to a new stem wagāta-, as this process has only been observed in OH (Melchert 2000: 65).Secondly, as conceded by Kloekhorst and Rieken, a noun with a suffixal complex *-ó/éh2-tos-is difficult to make sense of etymologically-there are no known morphological parallels among the Anatolian languages.These problems are resolved if we rather assume an original common gender *o-stem with an archaic acc.pl. in -/as/.42Such an interpretation is coherent with all aforementioned OS attestations.Accordingly, see examples (1) and (2).43 39 This has been suggested already by Oettinger (1976: 25-26), who saw the u-vocalism as intrusive in the acc.pl.c.enclitic pronoun =us, coming from athematic nouns with an ending originating in *-m̥ s.The original form would as such be =/as/ < *-oms#.& Melchert (2008: 252).41 This goes for all attestations where the preceding sign is visible.On others, such as KBo 20.5 rev.5, the preceding sign is broken off.42 This analysis was made already by Hoffner (1974: 188).43 The other examples occur in contexts too fragmentary to allow grammatical analysis.Note that also on KBo 25.79 obv.8 the form ⟨NINDAwa-ga-a-ta-aš⟩ is preceded by the numeral ⟨2⟩, but since this text is a list the nominative may be the underlying case (see Hoffner & Melchert 2008: 243).
Indo-European Linguistics 10 (2022) 3-32 (1) KBo 20.33 obv.12 (OS) This analysis solves the issue of word formation-derived formations in *-o-toare well attested in Anatolian (see Melchert 1999: 368-372).Moreover, the word is rendered semantically coherent: it is an āta-derivation of the verb 'to bite' , fitting its meaning as a type of bread.44There can be no doubt that the penultimate syllable is accented on account of the frequent plene spelling and the lenition of the original suffix *-to-by Eichner's first lenition law, consequently proving that the ending syllable was unaccented.45 David Sasseville (pers. comm.)notes that the possibility of NINDAwagātagoing back to an original common gender stem formed with the suffix *-teh2should be considered as well.46If the acc.pl.wagātas goes back to a form in *-teh2-ms#, it cannot reveal anything about the outcome of *-oms#.However, the *teh2-class is poorly represented in Hittite with only three possible continuants, all of which have been reanalysed as neuter stems (see Rieken 1999: 250-258 for a comprehensive treatment).Moreover, according to Rieken,the 44 On account of the root meaning perhaps '(bite-sized) piece of bread' or, with Badalí & Zinko (1989: 81), 'Imbißbrot' .45 It is potentially controversial to posit an accented o-grade as the leniting factor.One could also follow Rieken (1999: 197) and Melchert (2020: 272) and posit the base for the toderivation to be a formation with *-éh2-, i.e., *uVh2g-éh2-to-instead of *uVh2g-ó-to-.46 See Sasseville 2015: 291-292 for evidence of this class in Luwic.
billing Indo-European Linguistics 10 (2022) 3-32 semantics of the suffix in Hittite concern possession, which is hardly compelling for NINDAwagāta-.For these reasons, Melchert's analysis is given credence here, although an original stem with desinential *-eh2-cannot be excluded formally.
Provided that the analysis of NINDAwagāta-in the preceding paragraphs is correct, it stands to reason that all the common gender barytone a-stems, a large nominal class, received their acc.pl.ending from another stem type.This would be unsurprising on account of the resulting case ambiguity-the acc.pl., gen.sg., nom.sg., and dat/loc.pl.would all have the same ending -/as/ in earlier stages of Hittite, motivating the introduction of new ending.The situation is thus comparable to that of the non-ablauting i-stems (see Section 4.2).

4.4
Analogical spread of acc.pl.c.endings In some stem types, prominently the non-ablauting i-stems and the barytone a-stems, we find an acc.pl.c.ending allomorph different from what we may plausibly derive by sound law.Thus, the endings for these classes ought to be secondary.The motivation for analogy has been made clear in the preceding sections: the stems in question ended up with indistinguishable acc.pl.c.endings by sound law (*-/is/ and -/as/, respectively), creating pressure to adopt new endings.
For the non-ablauting i-stems, it is evident that their secondary ending is -/us/.The most likely model is found in the ablauting i-stems, which received the ending -/us/ by sound law.This spread thus implies that the ending -/us/ became associated with i-stems in general.As for the barytone a-stems, it is not possible to determine whether they received -/us/ or -/os/ with any certainty.The source of their ending is therefore better left unstated.

4.5
Proposed sound laws and the behaviour of final *-ms# All etymological inputs required for the proposed scenario to be valid have been established in Sections 4.1 through 4.3.It is notable that the outcomes of sequences ending in *-ms# are symmetrical to those already commonly assumed for sequences ending in *-m# with regard to vocalism.For clarity, all these sound laws are presented in Table 4 along with examples for each development.

5
The acc.pl.c. of hēu-'rain' The word for which we have the highest amount of plene attestations in the acc.pl.c.ending, Hitt.hēu-'rain' , has not been included in the preceding dis-47 But note also the diverging opinions summarised in Kimball (1999: 331-332).If completely uniform behaviour of *m word finally (> /n/) and before final *s is assumed, it would also be conceivable that the assimilation occurs at a point at which the *m has yielded an intermediate *n, a less controversial development (see Kimball 1999: 326-327).
8; OS).Although the final sign sequence -⟨mu-uš⟩ leaves the ending vocalism unspecified, we can surmise that the inherited ending must have been -/os/ on the basis of /ʔitáːlamos/, which belongs to the same original stem type (see Section 4.1).The originally ablauting stem hē(a)u-is changed into a non-ablauting u-stem hēu-from MH times onwards (Weitenberg 1984: 379-380;Kloekhorst 2008: 341).As such, it is clear that the forms ⟨ḫé-e-u-uš⟩, ⟨ḫé-e-ú-uš⟩, and ⟨ḫe-e-mu-ú-uš⟩ are all later secondary formations, exclusively appearing in NS texts, some in NH compositions.Among these forms, those spelled with ⟨ú⟩ run counter to what we would expect for a u-stem.
There seem to be two main possibilities available to explain the unexpected forms with ⟨ú⟩.One option is to assume some productivity of -/us/ at a very late stage of the language, ⟨ḫé-e-u-uš⟩ representing an older form /χéːos/.51 In support of this, there are a few indications that the tablets displaying -⟨ú-uš⟩ were written later.The tablet KUB 28.5 containing -⟨ú-uš⟩ is classified as LNS in the Konkordanz (Košak 2002(Košak -2022)).Moreover, the younger version of the sign ⟨ḫa⟩, indicative of the latest NS layer iiic (Weeden 2016: 163 with further references), occurs in all tablets except KBo 13.245, which displays -⟨u-uš⟩, itself dated to Muwatalli ii at the earliest (cf.Galmarini 2013: 3384).Note, however, that the iiic ⟨ḫa⟩ also occurs in KUB 16.37 obv.7 containing -⟨ú-uš⟩.We may also adduce the use of the logogram ⟨UGU⟩ 'up' on KUB 16.37 with -⟨ú-uš⟩ (ii 7), which in historical texts is almost exclusively attested from the time of Hattusili iii and onwards (Weeden 2011b: 553 & 627), i.e., post-Muwatalli ii.52 Complicating the picture, KUB 19.50 with a less probative form in -/os/ contains the iiic version of ⟨ki⟩ with an additional vertical and the fragment KBo 43.137 with the puzzling form ⟨ḫe-e-mu-ú-uš⟩ contains the older version of the sign ⟨ik⟩.53 51 The form ⟨⸢er⸣-ḫu-ú-š=a=kán⟩ was determined as non-probative in Section 2.1.However, if there was some late productivity of -/us/, it is possible that this form was formed at a stage in the language at which the sequence /χu/ was permitted (note the NS attestation).52 The logographic writing ⟨DÙ-zi⟩ 'does' on the same tablet (iv 6) may also be relevant, since it is common in historical texts from Hattusili iii onwards, but less so since it is also frequent in texts of Mursili ii (Weeden 2011b: 360-361).The fact that KUB 16.37 is an omen text, a genre where "late" scribal practices may have been more widespread at an earlier time, should also be kept in mind (cf. Weeden 2011b: 362-363).53 Melchert (2020: 271) also concedes that the form is puzzling and attributes it to a spelling error.This would certainly align with the argument put forward in the present article, as an erroneous spelling for ⟨u⟩ (i.e., reflecting /χéːmos/) is expected on account of the ustem declension.
Indo-European Linguistics 10 (2022) 3-32 This is to my mind the optimal scenario to account for the forms in Table 1 (Section 2).As an alternative, one could also envision a scenario in which a source of -/us/ was the primary barytone *o-stems, either in addition to or instead of the ablauting i-stems.55Under this analysis, an unaccented PIE sequence *-oms# would give Hitt.-/us/.I hold this to be less probable for the following reasons: 1.There is to my knowledge no solid positive proof of -/us/ (nor of -/os/) as the ending of the barytone a-stems.2. Hitt.NINDAwagāta-discussed in Section 4.3 would remain problematic.3. The parallel developments in Table 4 (Section 4.5) would be rendered invalid, leading to a less economical scenario in terms of historical phonology.The input sequence *-oms# would require special pleading in relation to the outcome of *-om#.

table 3
Hittite acc.pl.c.forms spelled with ⟨ú⟩ OH/MS), a partitive genitive use is likely underlying with the new gen.pl.ending -/as/.This is clear on KUB 2.6 v 37-40, where the word is referred back to by means of the common gender enclitic pronoun =/an/: nu=kan IŠTU GIŠBANŠUR DINGIRLIM 1 NINDAwagatas [ ] dāi nan ANA LÚ.MEŠE.DÉ.A URUArinna pāi 'he takes one of the pieces of bread and gives it to the blacksmiths of Arinna' .For the rare partitive genitive, see Hoffner

table 6
Distribution of acc.pl.c.allomorphs