3.2.1 Distribution

Agreement tends to be realized as an affix, while clitic doubling tends to be realized as a morphophonological clitic.¹⁰ In the Spanish examples in (11) and (12), for instance, not only is the agreement morpheme bound to its host phonologically, but each is also bound to the other morphologically, as neither can stand alone. In this sense, the agreement marker and its host are complementary. This is generally not the case for clitics, however. While the clitic in (12) is phonologically dependent on its host, the host is not morphologically bound in the same way as an agreement marker, as it does not need to be made complete by a clitic. The same distinction holds of the Shughni agreement suffixes and past-tense clitics. Although both are complementary, the hosts of agreement suffixes – i.e. present stems – cannot occur alone, whereas any element which hosts a clitic must be able to occur alone.

The Shughni past-tense clitics display a number of the properties of morphophonological clitics outlined in the seminal work of Zwicky (1977) and Zwicky & Pullum (1983). First, like the Spanish clitics above, they cannot bear stress. And second, they appear outside all affixal material, as shown in the examples below. In (16), the clitic appears after the infinitival suffix-ōw and the locative suffix -and. In (16), it appears after the plural suffix -ēn:

Moreover, these clitics can attach to phrases of many different types. That is, unlike affixes, they are not selective with respect to the type of host they select; rather, a number of constituent types may occupy first position, and a clitic, if present, simply attaches to the constituent in first position. Examples (17)–(20) show a clitic attaching to an NP, AP, PP, and V, respectively:

The distribution of these morphemes is in stark contrast to the present-tense agreement suffixes, which attach only to present-tense verb stems. With respect to this diagnostic, past-tense clitics in Shughni behave as morphophonological clitics rather than affixes.

3.2.2 Similarity to pronouns/determiners

A doubled clitic is more likely to bear resemblance in form to its corresponding pronoun or determiner than an agreement morpheme. Again, this follows from what we know about the nature of clitics and agreement morphemes. If a clitic is a D⁰-like element, then it should be no surprise that it resemble the full pronominal form or determiner whose φ-features it matches. There is no such expectation for agreement morphemes, which are simply the spell-out of a syntactic relation.

Importantly, this criterion should be used with some caution, as agreement morphemes may in fact resemble their corresponding pronouns. This follows from the well-known historical trajectory of these morphemes from pronoun to clitic to agreement (Ariel 2000). This criterion seems to be more helpful in comparing two phenomena within the same language. That is, within a single language, if the morphemes of one paradigm appear more similar to the forms of pronouns or determiners than those of another, then it is more likely that the former are the result of clitic doubling.

This is the type of situation we find in Shughni. Although the paradigm of present-tense suffixes and past-tense clitics are nearly identical in form—differing only in two cells, the second- and third-person singular—the second-person singular clitic form clearly bears more resemblance to the full pronoun form than the second-singular agreement suffix. Compare the second-person singular pronoun tu to the agreement suffix -(y)i and the clitic =(a)t, as shown in Table 5 (the second-person singular pronoun has the same form in the direct and oblique case – see Tables 1 and 2).

The voiceless consonant [t] in the second-singular clitic does not assimilate in voicing to its preceding sound, unlike the third-singular agreement affix, which assimilates to its preceding sound in voicing. Instead, if the preceding sound is a voiced consonant, an epenthetic vowel is inserted and the voiceless consonant is preserved (e.g. chīd=at). Hence, the second-singular clitic retains its similarity to its corresponding full pronoun, even in situations where phonotactics dictate it should undergo assimilation.

Taken at face value, the difference in forms between affixes and clitics may seem so slight as to be insignificant. However, what is important is that when compared to agreement suffixes, past-tense clitics bear more resemblance to full pronouns. I suggest here that the near syncretism of present-tense affixes and past-tense clitics in Shughni corresponds to the nature of the language’s ongoing shift toward nominative-accusative alignment. While I maintain here that the Shughni past-tense clitics are indeed clitics rather than affixes, it should not be surprising that, as the shift in morphosyntactic alignment progresses, the present-tense affixes and past-tense clitics show increasing similarity in form and distribution as they fulfill increasingly similar functions in the language. From a generativist perspective, this amounts to the idea that φ-features on T⁰ result in formally similar morphology, regardless of whether they are agreement morphology or a doubled clitic. This syncretism stands in contrast, for instance, to the corresponding agreement and clitic morphemes in the more robustly split-ergative languages Davani and Pashto, which differ rather significantly in form.

3.2.3 Default morphemes

Default morphemes are typically used to fill a morphological slot dedicated to agreement in cases where the agreement relation has failed. According to Preminger (2009), features which go unvalued due to a failed agreement relation simply retain their preexisting values, which may be in turn spelled out as default morphology (see also Preminger 2014 for discussion on failed agreement relations and their outcomes). Clitic doubling, on the other hand, “refers to the very creation of a feature-matched pronominal morpheme on the basis of an existing noun phrase”, and therefore “its failure should result in the absence of such a morpheme altogether” (Preminger 2009: 623, emphasis mine).

Hence, the discrepancy between agreement and clitic doubling with respect to default morphology is to be expected given the nature of these two phenomena. Moreover, as noted above, agreement morphemes are often morphologically co-dependent with their hosts. As such, it is no surprise that their slot must be filled by some morphological material, even if this material does not reflect the φ-features of any DP in the clause. In the case of clitic doubling, on the other hand, we are dealing with the movement of a D⁰-like morpheme; if, for whatever reason, this morpheme is not generated, then nothing can be moved and no morphological material is spelled out in the slot where the clitic normally appears.

It is clear that the Shughni past-tense agreement clitics lack a default morpheme (see Table 4). Unlike present-tense suffixes, there are instances in the past tense when the slot where a clitic generally appears is not filled, as in (5). (This pattern is discussed further in Section 4.) Although it is common cross-linguistically that certain cells in an agreement paradigm, often third-person singular, be null, the Shughni past-tense clitics do have an overt morpheme occupying the third-singular cell. The morpheme =(y)i appears for all third-singular subjects of transitive and unergative verbs, but does not appear for unaccusative subjects, a pattern which was exhibited in (3)–(5). In this sense, the third-singular cell in the paradigm of Shughni past-tense clitics is distinct from an empty cell in an agreement paradigm, for which overt morphology does not appear under any circumstances.

The three properties of the clitics discussed in this subsection – their distribution as morphophonological clitics; their relative formal similarity to pronouns; and their lack of a default morpheme – are all suggestive of clitic doubling.

3.3.1 Obligatoriness

Agreement tends to be obligatory, while at least some instances of clitic doubling are optional. Take, for instance, the following examples from Rioplatense Spanish, where the third-person singular object clitic =lo is optional, but the third-person agreement suffix -a is obligatory:

In Shughni, there is never a case in which the use of a clitic is optional, as was the case in the Spanish example in (21). It is ungrammatical to leave out a past-tense clitic in all cases except when there is a third-person singular unaccusative subject, and in these cases it is always ungrammatical to have an overt past-tense clitic. The following examples illustrate that the use of a clitic is not optional with constructions where the subject is not third-singular unaccusative:

Now, to see why obligatoriness is not relevant in the case of Shughni, consider that under many analyses (e.g. Preminger 2019), it is not the clitic-doubling operation itself which is optional; rather, what is variable is the presence or absence of features which trigger movement of the DP in question to a position from which it can be clitic doubled. This gives the illusion that the clitic-doubling operation is optional, but in fact it is obligatory if an argument is in a position from which it can be clitic doubled. Note further that the same group of features (e.g. definiteness, animacy, etc.) which triggers clitic doubling is often the exact same set of features that triggers Differential Object Marking (DOM), as in Bossong (1985; 1991), an independent reason to believe that the object has moved to a different position from which clitic doubling is obligatory, and that the clitic-doubling operation is not optional.

If clitic doubling is realized by way of a probe somewhere in the CP-phase searching downward for a viable DP-target, then objects which are generated inside of VP would virtually always have to move up to the edge of the phase to be accessible for this operation. This is not the case for subjects, of course, as external subjects would be base-generated in a position from which they can be doubled without any movement at all. Moreover, it follows that in a language where subjects are clitic doubled, only internal (i.e. unaccusative) subjects may fail to be clitic doubled. And indeed this prediction is borne out in Shughni. As we will see in the discussion in Section 4, feature-driven movement is a necessary step for Shughni VP-internal arguments (i.e. unaccusative subjects) to reach a place in the structure where they are be visible for the clitic-doubling operation. External subjects, however, are generated higher than VP and are always clitic doubled. In this sense, because it is subjects which are the targets of clitic doubling in Shughni, we should expect the operation to be (more) obligatory than in languages where objects are doubled.

This concept is illustrated in (25) and (26). Note that it is assumed that unaccusative subjects are generated in the same position as an object DP, as in (26), while unergative and transitive subjects are base-generated in Spec, vP, as in (25).

I thus conclude, along with Preminger (2019), that obligatoriness alone is not enough to determine a morpheme’s status as agreement or clitic doubling and that we must take into account the effects of factors such as the structural position of the arguments in question. Similar arguments are provided below regarding the relevance of the semantic interpretation of the DP and binding effects.

3.3.2 Relevance of the semantic interpretation of the DP

In many cases, a DP may only be clitic doubled if it has some relevant semantic property which sets it apart, often definiteness or animacy (see e.g., Kramer 2014; Preminger 2019). Such features, however, do not typically modulate the realization of agreement. Semantic interpretation is relevant, for instance, in Spanish clitic doubling, where a DP must be interpreted as both definite and human to be clitic doubled, but it is not relevant for agreement in Spanish.

The realization of past-tense clitics in Shughni is not dependent on semantic interpretation of this kind. Instead, these morphemes appear with all subjects regardless of definiteness, animacy, or any other property. The following examples illustrate that in the Shughni past tense, a subject takes an overt clitic regardless of whether it is definite, as in (27), indefinite specific, as in (28), or indefinite non-specific, as in (29).

Examples (30) and (31), for their part, show that both animate and inanimate third-singular subjects trigger a clitic:

Finally, examples (32)–(35) show that clitics are obligatory with both universal and negative quantifiers, as well as wh-words.

The idea that the semantic interpretation of the subject DP should not be relevant for the clitic doubling of external subjects follows the same line of logic as that for obligatoriness discussed above, namely that the position of external subjects within the CP-phase renders them available for the Agree operation which precedes clitic doubling without any prior movement taking place. On the other hand, when an object is clitic doubled, it is generally by virtue of some semantic feature(s) which trigger its movement into a domain where it is visible for Agree (e.g. Diesing 1992; Aissen 2003; Kalin 2018; see Preminger 2019 on the notion that the clitic-doubling operation first requires syntactic φ-agreement to take place). In Spanish, then, it is the features [DEFINITE] and [HUMAN] which allow an object DP to move to the phase edge and, subsequently, be clitic doubled. In the case of subjects, only those generated within VP (i.e. internal subjects), must undergo such movement to be clitic doubled, as they do in Shughni by virtue of the features [PLURAL] and/or [PARTICIPANT] (to be discussed in Section 4). The notion that the clitic doubling of external subjects should not be dependent on semantic features is indeed borne out in Shughni, where all external subjects are clitic doubled regardless of semantic interpretation.

3.3.3 Interaction with binding

Finally, doubled clitics have been shown to interact with binding relations, while agreement morphemes do not interact with binding. This is expected given that clitics are pronoun-like morphemes which undergo movement, and that pronouns play an important role in establishing binding relations (Anagnostopoulou 2003 on Greek; Kramer 2014 on Amharic; Harizanov 2014 on Bulgarian). On the other hand, agreement morphemes are the morphological spell-out of feature bundles and therefore cannot refer in the same way as clitics. Moreover, while movement is always involved in clitic doubling, it is not necessarily involved in agreement, and hence hierarchical relations between DP’s are not affected in the case of agreement.

There is no evidence that past-tense clitics in Shughni affect binding relations. However, I argue here that even if these morphemes are syntactic clitics, we should not expect them to affect binding relations. I present three pieces of evidence for this conclusion and conclude that the Shughni past-tense clitics are indeed the result of clitic doubling.

The first situation in which we might expect a change in binding relations is when an object clitic moves above a subject, thereby reversing the hierarchical relation of subject and object. On the other hand, if a subject is doubled, then, all else being equal, it should maintain its relative position in the structure with respect to the object. Compare a moved object clitic in (36) to a moved subject clitic in (37):

In (36) the doubled clitic of the object is now higher in the structure than the subject DP, which is in its base-generated position of Spec,vP. In (37), however, the relative positions of the subject and object remain unchanged. Although the doubled clitic of the subject has moved higher in the structure and is adjoined to X⁰, it still maintains the same position relative to the object DP, which is in its base-generated position of Spec,VP.

Secondly, clitic doubling has been shown to repair binding issues like backward pronominalization (see Kramer 2014: 604–605 for a clear instance of this type of repair in Amharic). According to Kramer, the fact that syntactic clitics can affect binding relations is to be expected on the view that they are pronoun-like elements, and pronouns are inevitably implicated in binding relations. In Shughni, however, repairing instances of backward pronominalization is rendered unnecessary by the existence of the reflexive genitive pronoun khu ‘self’, which is always bound by an overt DP in the clause. Hence, there is no problem with interpreting the following sentences, which may result in issues of backward pronominalization in other languages, because the noun modified by khu must always be co-indexed with an overt NP. This is true whether the construction involves an agreement suffix, as in the present-tense example in (38), or a clitic, as in the past-tense example in (39):

To be sure, if the third-person possessive adjective wi – which is identical to the third-person oblique pronoun – is used instead of the possessive pronoun khu, it must not be co-indexed with a DP in the clause:

Finally, we might expect inappropriate binding relations to occur in Shughni between a doubled subject DP and its corresponding clitic. In particular, a violation of Principle B would occur in cases where the doubled subject clitic, qua pronoun, is bound by the subject DP within the same TP. This situation is illustrated in (42), where the subject DP in Spec,TP binds the doubled subject clitic adjoined to T⁰:

However, as we will see in Section 4, Shughni has an EPP-feature on T which does not target subjects specifically; rather, any constituent can move to its specifier position. Like related movement in V2 languages, the choice of which constituent to move to first position is linked to pragmatic notions of focus and topicality. With this in mind, I take this movement in Shughni to be an instance of Ā-movement, which is generally taken not to create new binding relations (see van Urk 2015 for an overview of the distinctions between A-movement and Ā-movement). Therefore, even in examples like (42), where a subject DP appears to bind its associated pronominal clitic, we should not expect ungrammaticality due illicit binding relations, as the former has reached the specifier of TP via Ā-movement (see Baker & Kramer 2018 for further discussion on the connection between EPP, clitic doubling, and binding relations).¹¹ For these reasons, the fact that Shughni past-tense clitics do not interfere with binding relations is irrelevant in determining whether these morphemes are the spell-out of agreement or doubled clitics.

Before concluding this section, note that I purposefully leave out one of Kramer’s diagnostics—allomorphic variation depending on the features of T—which is also alluded to in early work on clitics and affixes (e.g. Zwicky & Pullum 1983) and in Nevins (2011). This diagnostic effectively states that the form of agreement morphemes may vary with features of the functional head with which it is associated (e.g. tense features on T⁰), while doubled clitics, as D⁰-like morphemes, are both more fixed in form and not as closely associated with a functional head in question and should thus not vary in this way.

In the case of Shughni, this diagnostic could be applied to the past-tense clitics and used to argue for either agreement or clitic doubling, depending on one’s analysis. The paradigms of agreement suffixes and past-tense clitics are the only two variants of morphemes which expone the φ-features of DP’s in Shughni. The use of each depends solely on the type of verb stem in question: suffixes are used with present stems, and clitics are used with past stems. If we wished to analyze both paradigms as agreement, we could say that their difference in distribution and form arises from variation in features on the functional head with which they are associated. That is, agreement with T_PRS results in a suffix, while agreement with T_PST results in a morphophonological clitic. If, on the other hand, we wished to analyze the past-tense clitics as clitic doubling, we could use this same criterion in our favor. In particular, the fact that these morphemes do not vary in form or distribution, regardless of whether they are associated with a past or perfect stem, could be used to argue for their lack of variance with respect to aspectual features of T.

Furthermore, Yuan (2018: 55–58) argues that there is in fact no reason to believe that syntactic clitics cannot undergo allomorphy based on the features of the functional head which hosts them, as they are both structurally and linearly adjacent to this host. She cites as evidence instances in which the presence of two adjacent clitics seems to trigger allomorphy, as in the Spanish spurious se (Perlmutter 1971; Bonet 1995; Nevins 2007), and a phenomenon from the Yimas language of Papua New Guinea in which syntactic clitics undergo allomorphy based on the features of the functional head which hosts them (Yuan 2019). For these reasons, I leave the criterion of TAM-based allomorphy aside for the purposes of the discussion in this paper and conclude that the Shughni past-tense clitics are the result of a clitic-doubling operation.

4.2.1 Shughni lacks ergative-assigning v

As discussed above, Shughni past-tense clitics display nominative-accusative alignment everywhere except with third-person-singular arguments. Given how restricted this pattern is in the grammar, I see no motivation for positing that the language maintains an ergative-assigning v⁰ in its past tense. I therefore make the claim here that Shughni has a fully nominative-accusative system throughout its grammar. That is, the second-position clitics used to co-index the φ-features of past-tense subjects in Shughni are not the result of inherent ergative case assignment; instead, both past-tense clitics and present-tense suffixes in Shughni are the result of a φ-probe on T⁰ entering into a syntactic relation with an eligible DP. We will see in Section 5 that Davani shows a similar pattern of split alignment with respect to its past-tense clitics, but according to Moghaddam’s (2016) analysis, does indeed maintain an ergative-assigning v⁰ in its past tense.

An important feature—and, I believe, advantage—of this account is that it derives a non-canonical (split-intransitive) alignment pattern without recourse to an ergative-assigning v⁰. I take the lack of an ergative-assigning v⁰ in Shughni to indicate that it is at a different stage than Davani in the development from ergativity to accusativity. Importantly, vestigial ergativity, under the view advocated here, is not ergativity of the kind found in Davani or Pashto. Rather, this pattern is one which descriptively fulfills the argument-structure property of ergativity (Deal 2015), but is in fact the result of feature-driven DP-movement which operates for all internal arguments except third-singular.

4.2.2 Feature-driven movement in Shughni

Now, if the pattern of vestigial ergativity in Shughni is not derived via an inherently ergative property within the language’s grammar, then how exactly does this phenomenon come about? I propose here that certain internal arguments in Shughni undergo feature-driven movement to the phase edge, a position from which they can be targeted by an Agree relation which results in a second-position clitic matched to their φ-features. Feature-driven movement in Shughni, I argue, is similar in nature to the object shift of Davani in that a probe on a functional head searches downward for a DP with a certain set of features and that movement only occurs if a viable DP is found. In Section 5 it will be seen that the features which allow internal arguments to move in Davani are [HUMAN], [SPECIFIC], and [HIGHLY AFFECTED], a set of rather common features in the phenomenon of DOM (e.g. Aissen 2003; Naess 2004; Kalin 2018). A viable DP, if found, moves upward in the structure into the domain of the probe.

In Shughni, however, the relevant features are not semantic features such as definiteness, but rather the grammatical features [PLURAL] and [PARTICIPANT].¹³ Importantly, an internal argument in Shughni may have either or both of the features [PLURAL] and [PARTICIPANT] to move up, and, hence, it is those which are least marked with respect to person (third-person) and number (singular) which fail to move. The features [PLURAL] and [PARTICIPANT] appear to be a rare combination to modulate feature-driven movement of this kind, but the Shughni pattern is nonetheless in line with the cross-linguistic pattern where arguments which are more marked on a given scale are targeted by the probe and moved.¹⁴ Shughni pronouns and their features are shown in Table 10. Light gray cells represent pronouns which are endowed with one of the two features, while dark gray cells represent those which have both features.

An internal subject with the necessary feature(s) in Shughni moves out of VP to the phase edge, where it becomes visible to a probe on T⁰. The syntactic relation established between the probe and the moved DP triggers a clitic matched to the DP’s φ-features, which moves up in the structure and appears in second position at surface structure.¹⁵ This movement and the subsequent syntactic relation between probe and DP is displayed in (47):

Internal arguments in Shughni which lack both of the features [PLURAL] and [PARTICIPANT] – i.e. third-singular internal arguments – do not undergo feature-driven movement.¹⁶ Moreover, I propose here that Shughni has an EPP-requirement on T⁰, but the EPP feature in Shughni does not require that unaccusative subjects – or any subject for that matter – move to Spec,TP. Rather, the EPP feature on T⁰ in Shughni simply requires that some constituent, not necessarily the subject, occupy the specifier position of TP.

I take EPP-movement in Shughni to be an instance of topic- or focus-related Ā-movement and propose further that it is the constituent which has moved to the specifier of TP in Shughni which hosts the past-tense second-position clitics. Movement of this kind is similar to the movement that derives V2 word order in languages like German and Dutch, where the moved element precedes an unaccented finite verb. In Shughni, this movement is needed to provide the host for second-position clitics, including the φ-feature-bearing past-tense clitics. However, while the first element of V2 clauses in Dutch and German is generally taken to occupy the specifier of CP, there is evidence that the first element in the Shughni clause occupies the specifier of TP. This is seen through the fact that in embedded clauses, these clitics must attach to the first constituent following the complementizer, and never to the complementizer itself, as exhibited in examples (48) and (49) below. Here, the second-person singular clitic =t must attach to the first constituent following the complementizer idi ‘that’ – as in (48) – and is prohibited from attaching to the idi itself – as shown in (49):

In addition, the existence of (non-pronominal) second-position clitics in non-past tenses suggests that this type of EPP-movement is not restricted to the Shughni past tense. For instance, the second-position clitic =ta, which indicates future tense, behaves identically to past-tense clitics in its distribution; that is, it can attach to any type of constituent, including subjects, and as in (50), as well as non-subjects, as in (51), as long as it occurs in second position within TP:

Internal subjects in Shughni must therefore undergo feature-driven movement to be eligible for agreement, and those lacking the relevant features stay low within the phase and are not found by the probe on T⁰. Furthermore, it is well known that cases where a probe does not find a viable DP do not necessarily cause the derivation to crash. Instead, the derivation may simply proceed as normal, with failed agreement operations often resulting in default morphology occupying the slot where the spell-out normally occurs, and failed clitic-doubling operations often resulting in no morphology at all occupying the clitic slot (Preminger 2009; 2014). Here, I argue that the failure of the probe to find the third-singular internal subject does not cause the derivation to crash; the result is simply the lack of a third-singular clitic =(y)i co-indexing the internal subject, as was the case in (45). Recall, further, that the lack of any morphology occupying the clitic slot in examples like these was an integral piece of the clitic-doubling analysis presented in Section 3. The structure for such an example is given in (52):

Third-singular subjects of transitive and unergative verbs (i.e. A and S_A) also lack the features necessary for movement, but, crucially, are generated high enough in the structure to be accessible to the probe responsible for the appearance of a second-position clitic. This is shown in the structure in (53), where the external subject in Spec,vP represents the subject of any transitive or unergative verb in Shughni. Here, the probe on T⁰ successfully finds the subject, which ultimately results in the appearance of a second-position clitic:

Note further that, on the analysis presented here, movement of this kind is not restricted to internal subjects, but occurs for internal objects as well. I follow Moghaddam in proposing that objects which undergo feature-driven movement in Shughni tuck in within vP (as in Richards 2001), a mechanism which serves to maintain the base order of hierarchical relations. Thus, even after movement and tucking in, internal arguments which undergo movement of the kind in (47) are ultimately still in a position lower than external subjects. The probe on the functional head would therefore still find the external subject before the moved object. This is shown in (54):

I further posit that the same movement shown above in the past tense also occurs in the present tense. That is, third-singular subjects of unaccusative verbs also fail to move in present-tense constructions. If this analysis is on the right track, then the agreement probe associated with T⁰ in the present tense would likewise fail to find a viable DP in the case of third-person singular unaccusative subjects, and the agreement morphemes associated with these subjects are in fact default morphemes. An independent piece of evidence suggesting that the default morpheme is indeed identical to the third-person singular agreement morpheme is that it is used in both weather predicates and clausal predicates, as in (55) and (56), respectively:

Crucially, the reason that even in these cases the suffix slot is filled in the present tense is because it is an agreement morpheme rather than the result of clitic doubling. Of course, it is not uncommon that default agreement morphemes be identical in form to third-person singular morphemes (see e.g., Preminger 2009; 2014, and references therein), and it would therefore be unsurprising if this were the case in Shughni.

4.2.3 Case assignment in Shughni

Finally, one may wonder how case assignment works in Shughni, given that third-singular unaccusative subjects are not in the same syntactic configuration as other subjects. In particular, under a system of inherent case assignment in which case is assigned via a probe-goal relation between a functional head and the DP in its specifier – the approach adopted by Moghaddam for Davani – it is not immediately clear how third-person singular unaccusative subjects in Shughni would be licensed, as they remain within VP while all other subjects are either generated in the specifier of vP (A and S_A), or move to this position (non-3SG S_O). One solution would be to adopt a dependent-case approach for both Shughni and Davani. In Shughni, nominative case would be assigned to the highest DP in the structure, regardless of its specific syntactic position (i.e. default case; see Baker & Bobaljik 2017 for an overview). In Davani, on the other hand, ergative case would be assigned to the highest of two DPs in the past tense, with the lower of the two receiving nominative case. A similar approach has been used elsewhere in the literature for languages with non-accusative alignment. Ershova (2019), for instance, adopts a dependent-case analysis for the ergative language West Circassian (NW Caucasian), a language which is like Shughni in displaying a direct-oblique distinction. In Ershova’s analysis, a DP is assigned oblique (dependent) case by virtue of being c-commanded by another DP within the case domain of TP. A similar approach could be taken for Shughni.

An alternative solution would be to posit that nominative case in Shughni (and Davani) is the result of the absence of case assignment in the syntax, as argued for by e.g., Kornfilt & Preminger (2015). Case assignment in these languages is a topic for future research, but I see no reason at this point why a similar account based on either dependent case or nominative as the absence of case cannot be applied to both Shughni and Davani.