3.1 Subject versus non-subject focus

With regard to focus constructions, which form the major topic of interest in this paper, Dagbani allows both ex-situ and in-situ focus. With ex-situ focus, the element that is in focus is moved to the left periphery of the sentence where the entire constituent is followed by a focus marker, either ka or a nasal consonant n,m or ŋ (which is homorganic with the place of the following consonant). For convenience we will refer to this marker as n, but the reader should bear in mind that its realisation is determined by the phonology of the following consonant.

The choice between the markers is at first glance conditioned by the grammatical role of the focussed argument, with subjects appearing with n, and all other focused items appearing with ka.⁵

Though we will diverge from this viewpoint, for reasons that will become clear shortly (see section 3.2), the view up to now taken in the literature (for instance Issah 2012; 2015) is that the distribution of the focus markers is determined by grammatical role. That is, n combines with subjects in focus, and ka combines with all other focussed elements. This is supported by the fact that a similar division of focus markers apparently dividing subjects and other arguments is seen in related Mabia languages.⁶ For instance, the following from Gurene (Dakubu 2003) shows that there is an optional focus marker n which marks focussed subjects, and another marker ti used to mark non-subjects.

We illustrate with two further examples, both Gur (Mabia) languages. Firstly, Kusaal (Abubakari 2016):

Secondly, (the Pisaali dialect of) Sisaali (Dumah 2016):

This is not an exhaustive list of languages with this property and we refer the reader to Kalinowski (2015) for a more comprehensive survey of focus marking in African languages, where the Mabia languages are included in the survey.

Returning to Dagbani, it is important to stress that ka and n are focus markers, since they only appear in contexts of new information focus (questions, answers, contrastive focus etc). A reviewer questions whether they could be markers that indicate any A’-dependency. We claim that they are not, which can be shown by the following sentences, all canonical instances of A’-movement, but not focus. As can be seen, n and ka do not show up in relative clauses, tough-movement constructions, or in comparative clauses.

Note that with the last two instances, tough-movement and comparative clauses, respectively, it is not immediately apparent that A’-movement is involved at all. Relative clauses, however, do seem to involve similar properties to English, and they do not allow for n and ka. We leave a fuller investigation of A’-movement in Dagbani for future work, but it suffices to note here that n and ka are focus markers, and not general indicators of an A’-dependency.

As we have seen, n and ka appear to mark whether a subject or a non-subject has been focussed. Further evidence of a split between subjects and non-subjects can be seen in the behaviour of the two classes with regards to in-situ focus. Focussed subjects are not allowed to appear in-situ, whilst all other elements are. It is easy to see that in-situ focus is possible with non-subjects. We see that (16-b) can serve as the answer to the question in (16-a), when the object is left in its base position.⁷

Since ka appears only in the left-periphery, and never in in-situ positions, we must rely on the context determining that we are truly dealing with focus here. Answers to wh-questions are generally taken to be focussed since they contain new information. Thus, movement to the left periphery is not obligatory for Dagbani focus.⁹ It is difficult to show that subjects do not allow for in-situ focus. With subjects, movement to the left-periphery is string vacuous; the canonical subject position is Spec,TP and already the leftmost element of the focus. However, one of the characteristics of in-situ focus in Dagbani is that the focus marker cannot appear with the in-situ focus. Thus, in (16-b), the sentence would be ungrammatical if ka were to accompany the object. We can utilise this property for subjects. If subjects were allowed to remain in-situ under focus, we would expect that they can appear without the focus marker, even when interpreted as in focus. The following pair of examples demonstrates that, leaving the subject in its base position without a focus marker yields a grammatical sentence, however the sentence is infelicitous in the context.

The interpretation of the sentence is infelicitous in this example. Thus, the focus marker is obligatory for subjects when in focus, and we take this to mean that in-situ focus is not possible for subjects, in contrast to other elements in the sentence, and that subject foci necessarily move to a left-peripheral position. There is no material that can intervene between the focussed subject and the position of tense. Adverbs that are traditionally used to delimit TP, such as finally (Mccloskey 1996a) appear to the right of the tense morpheme in Dagbani:

Thus, it is not possible to show that the subject moves to the left-periphery using this test, but we take the presence of a focus particle to the right of the subject to indicate that it has moved to the specifier of CP.

Dagbani is thus a language where focus can be optionally ex-situ or in-situ which is somewhat frequently attested in the languages of West Africa (see Hartmann & Zimmermann 2007a on Tangele; Hartmann & Zimmermann 2007b on Hausa; Hartmann & Zimmermann 2009 on Guruntum; and Hartmann & Zimmermann 2012 on Bura). As to why Dagbani allows both in-situ and ex-situ focus is doubtless an interesting question, but not one that is of concern to us here, and for a discussion we refer the reader to Issah (2018). For now, let us simply assume that whatever is responsible for driving movement to the left periphery is optionally present or operational in Dagbani, and thus, with certain exceptions, focussed elements are only sometimes compelled to move to Spec,CP.

In certain respects, some of this behaviour is not all that surprising. It has already been noted in the literature (Fiedler et al. 2010) that languages in the west African region (Dagbani being one of the languages in their study) show special behaviour regarding putting subjects into focus. Specifically, Fiedler et al. show that languages in this region mark focus on subjects differently and/or more robustly than on other elements, like objects or adjuncts. Dagbani is no exception here: subject focus is obligatorily marked, and it uses a different focus marker to other elements. Furthermore, it is not possible to focus subjects in-situ, which is possible for other elements.

Ex-situ focus always involves the focussed element appearing at the left edge of the clause, where it is followed by a focus marker, which as we have seen, varies according to the role of the focussed element. The element in the left periphery appears to be in that position by virtue of having moved there from its base position. This can be easily seen for objects, whose clause initial position contrasts with the regular position of objects, as well as the fact that when they are in this position, a focussed interpretation (with concommitant marking) is obligatory. Furthermore, we can see that this is a movement dependency because it is sensitive to island constraints. Consider the following example, where the focus is intended to lie only on one part of a coordination. It is not possible to move the conjunct to the left periphery and leave the rest of the coordination behind, which is a simple violation of the coordinate structure constraint (Ross 1967).

It is also not possible to move part of a coordination that lies in the subject position to the left periphery where it would combine with a focus marker.¹⁰

Instead, if one wants to focus part of a coordination, then the focus marker must appear to the right of the entire coordination, even if only one of the conjuncts is in focus.

So, whilst the conjunction can move as an entire unit, a single conjunct is not free to move alone.

There are of course various ways in which movement could play a role in the creation of ex-situ focus. There are known to be African languages which use a clefting strategy in focus constructions, such as Yoruba (Adesola 2005). A key diagnostic of such languages is that the element that occurs when making a focus construction is used elsewhere as a verbal element. However, in Dagbani, there is no evidence to suggest that a clefting strategy is employed in the contexts under discussion. The existential verb in Dagbani is nyɛ́, and not one of the markers that is used in focus contexts:

Furthermore, the focus markers can still appear in addition to the copula in a cleft construction (Hartmann & Issah 2018): Both focus markers, ka and n are used only in contexts involving focus, and do not serve any other verbal marking duty.¹¹ Thus, we assume that ka and n are focus heads in the left periphery, that both raise an element bearing focus to their specifier position.

3.2 Embedded subjects

Though characterising the split as subject vs. other captures the data that we have looked at so far, and fits in nicely with the observation of Fiedler et al., things quickly become more complicated once we factor in the behaviour of embedded subjects. Somewhat surpisingly, embedded subjects combine with ka instead of the expected n.

A couple of points are worth elaborating on here. The use of n is strictly forbidden in this case, and ka is the only choice. It is possible to have focus where the embedded subject moves to the intermediate CP, in which case n is used, and ka is ungrammatical.

However, if the embedded subject is focussed to the matrix left-periphery, it is obligatory that ka be used. The observation that emerges then, is that n is used for focus of a subject to the closest left-periphery to the subject, and ka is used otherwise. n should then be seen not as a marker of matrix subjects in focus, but rather a marker that appears when an subject in focus undergoes local movement to the left periphery (i.e. the subject is focused without crossing a clause boundary).

A second interesting observation regarding (24) is the use of a resumptive pronoun in the subject position of the lower clause. The resumptive is obligatory here. For all other types of arguments discussed above, the use of a resumptive pronoun in the position before movement is ungrammatical. Thus, non-local subject focus is unique in Dagbani in that it requires a resumptive in the place of the “moved” element, as can be seen comparing (26-a) with (26-b) and (26-c).¹²

A final observation regarding embedded subjects and their behaviour under focus is the fact that syntactic islands can be violated without any loss in grammaticality, such as in the embedded coordination in (27-a).

The ability to escape islands of non-locally focussed subjects does not just hold for coordinate structures, but rather other island effects as well, wh-islands and complex noun phrases in the examples below.¹³

This observation by itself does not appear too surpising. It is fairly well documented in the literature that the use of resumptive pronouns sometimes brings with it an ability to escape syntactic islands (McCloskey 1990; Shlonsky 1992; Saah 1994; Aoun, Choueiri & Hornstein 2001; Salzmann 2011; 2018). For Dagbani however, the use of resumptives does not appear to be forced by an island violation, but rather represents the usual strategy of non-local subject focus. Strikingly, in Dagbani, resumptives are not used as a general backup strategy for where movement fails. If we try to construct similar examples with extraction from an island within matrix subject or object positions, the use of a resumptive does not help, and the sentences remain ungrammatical, cf. (19-a).¹⁴

Thus, Dagbani seems to differ in that resumption is limited to a non-local subject position, irrespective of whether one is extracting from an island or not.

3.3 Interim summary

Whilst we started this section discussing how Dagbani appears to show a dichotomy in the behaviour of focused subjects versus all other focused elements, we have seen that it is in actual fact a three-way distinction. Yet this three-way distinction collapses into two different groupings. On the one hand, local subject focus differs from non-local subject focus and non-subject focus in that locally moved subjects require the focus marker to be n, and not ka. In this respect, non-local subjects and non-subjects behave alike. On the other hand, local subjects and non-subjects form a natural class in that neither require (nor allow for) the use of resumptive pronouns, behaviour that sets both sets of items apart from non-local subjects. The key findings are summarised in Table 1.

4.1 Movement to the left periphery

In the derivation where an element moves syntactically to the left periphery, we assume that the morpheme ka is the realisation of C which bears an interpretable focus feature, C_[iFoc]. The phrase which is interpreted as focussed bears an uninterpretable focus feature that must be associated with C_[iFoc]. We follow Bošković (2007); Abels (2012) and assume that the features that force movement are present on the moved element. That is, we assume that the presence of an unvalued information structural feature on the item that will be in focus, and its need for a value forces it to seek to move to the specifier of a projection assoction associated with a corresponding feature that is valued. The movement is driven by the need of the moved XP to probe downwards in order to obtain a value. Subjects are also compelled to move to Spec,TP in order to satisfy the EPP, and assume the same explanation underlying this (potentially due to the presence of a [uT] feature on the subject Pesetsky & Torrego 2007).¹⁵ In the following sentence, where the object búá ‘goat’ is in focus, it has an unvalued [uFoc] feature, and so moves to Spec,CP in order to get a value and license it, whereas the subject is compelled to move to Spec,TP in order to license its [uT] feature. Not shown is movement of the object through Spec,vP, though it is assumed that this movement would take place.¹⁶

Certain properties follow from this derivation. Firstly, since we are dealing with a movement derivation, we do not expect that syntactic islands will be able to be escaped from here. Furthermore, since we are dealing with a derivation whereby the element is moved into the left periphery, we expect that the base position is filled by a trace (or deleted copy) of the moved element. This has the effect that there is a gap in the base position of the object. Again, ignoring local subject movement for the time being, we propose that this is the strategy that is employed in non-subject movement, accounting for the fact that we do not observe these elements either escaping islands or being associated with a resumptive pronoun.

4.2 Base generation and resumption

The second strategy that Dagbani resorts to with ex-situ focus, we propose, is a strategy of prolepsis, whereby the focussed element is base generated where it appears in the left-periphery, and is associated with another element elsewhere in the structure. This is what is found with non-local subject movement, which the reader should recall is the only configuration that allows for a resumptive pronoun. Recall that these sentences superficially look very similar to those that are derived through the strategy outlined in the previous subsection, in that there is a focussed element in the left periphery, to the left of ka. Since ka, by assumption, is the realisation of C_[iFoc], then we must assume that in this derivation as well, the focussed element lies in Spec,CP. However, the superficial difference between non-locally moved subjects and non-subjects is that there is a resumptive pronoun in the subject position of the lower clause, whilst there is no corresponding resumptive with non-subject focus.

What we propose then, for this derivation, is that the element that occupies the specifier of Spec,CP is base generated directly there, and it becomes associated with a resumptive pronoun that acts as the subject of the lower clause. We assume that this is a relation of binding (following Mccloskey 1990), and not one of movement where the resumptive is the spell-out of a lower copy. Furthermore, we assume that the pronoun in the embedded clause obeys the movements that we would standardly expect. Thus, we are left with the following derivation, where we indicate movement relations with a solid arrow, and binding relations with a dashed arrow. The pronoun, which is generated as the specifier of vP, raises to Spec,TP to fill the EPP requirement on T. In the matrix clause, the focussed item is generated directly in Spec,CP, where it is associated with the resumptive pronoun in the lower clause so that the interpretations match. For the example in (24) (repeated below), we can give the derivation in (33).¹⁷

In this case, there is no movement relation connecting the element in the left periphery and the pronoun, and we thus expect that the connection between the two can “violate” syntactic islands, as we have observed is the case for non-local subject focus. This is of course an illusion of sorts: there is no island violation because there is no element moving out of an island. Note that the resumptive is obligatory in this derivation. We know from the examples above that ungrammaticality results if the resumptive is omitted from contexts of non-local subject focus. This is expected in this derivation: the resumptive is obligatory because it is required so that it can satisfy the EPP on the lower T, and receive the thematic information assigned to the lower subject. The element that lies in Spec,CP receives its interpretative properties, such as thematic role etc. through its association with the resumptive.

4.3 Why use resumption?

A question that arises now, is why should this second strategy exist? Using resumption in place of moving a subject is perhaps not all that surprising, and could arguably be the result of a Criterial Freezing effect in the sense of Rizzi & Shlonsky (2007), whereby certain positions, once occupied, freeze the occupants in place. Subjects are well-discussed to be potential candidates for such a position.

Why such criterial effects should hold remains unexplained, and so a more promising alternative to us seems to be a spate of recent research which has attempted to account for the immobility of subjects through a specific formulation of antilocality. These works have looked at phenomena such as Agent Focus in Kaqchikel (Erlewine 2016), that-trace and anti-that-trace effects in English (Douglas 2017) and the subject condition more generally (Bošković 2016). Such approaches have all proposed some variation on the theme of antilocality, where movement is too short to be licit. The papers each take as their starting point the following descriptive generalisation proposed by Erlewine (2016):

Each of the accounts differ from the others in how they propose to derive (34). Our aim here is not to adjudicate between them but rather provide extra support for its status as a descriptive generalisation or some equivalent that prevents movement from Spec,TP to Spec,CP.¹⁸ Both Douglas (2017) and Bošković (2016) suggest that it may be derived through the theory of labeling, a conclusion which we see as reasonable, and renders the subject position special, rather than accepting (34) as an overarching condition on A’-movement.

With this in mind, we can understand why the resumptive pronoun is necessary in non-local subject focus, rather than using the movement derivation that non-subject focus uses. The answer is that the intermediate stage of movement that would need to happen in a movement derivation is too short. The derivation would precede as follows, and shown graphically in (35). Firstly, the embedded subject moves from Spec,vP to Spec,TP to satisfy the EPP. Secondly, in order to move to the matrix clause, it would need to move to Spec,CP in order to escape the phase. Thirdly, it would move to the matrix Spec,vP to escape the lower phase in the matrix clause (assuming multiple specifiers are possible), before finally moving to the matrix Spec,CP. It is the second stage of this derivation that causes the problem, since the movement is too short. Effectively, when an element bears both [uT] and [uFoc], one of these features is not going to be licensed since a single element cannot move into the right positions to license both of them.

Using a proleptic derivation, however, of base generation in the left-periphery and a resumptive pronoun lower down in the structure allows for the best of both worlds: the specifiers of both CP and the embedded Spec,TP are able to be filled by different elements, with nothing compelled to move between the two. Prolepsis, and splitting the features across two elements that are interpreted as the same (through A’-binding) thus allows for a converging derivation where the subject is interpreted as in focus.

The resumptive pronoun strategy then arises as a way of being able to ensure that both the EPP on T, and the Focus feature in the left-periphery can be licensed. Due to antilocality, both cannot be carried out by a subject with a movement derivation, since the subject cannot make the movement from Spec,TP to Spec,CP.

4.4 Can the resumptive be the spell-out of a trace?

Before ending this section, we are now in a position where we can consider whether our prolepsis analysis of resumption in Dagbani is correct, by considering it in light of an alternative analysis of how resumption is formed. It has become clear that some resumptive pronouns can at times be the spell-out of a movement step, see amongst others Engdahl (1985); Boeckx (2003); Kandybowicz (2007); Sichel (2014); van Urk (2018). That is, whereas movements usually leave behind a gap, occasionally a pronoun can be insterted in place of said gap, if the position of the gap requires overt pronunciation (Landau 2006; van Urk 2018). It may be possible to recast the EPP requirement of Dagbani as a phonological requirement, such that all else being equal, it needs to be pronounced (see Salzmann et al. 2013 on the idea of the EPP being phonological in nature).

Dagbani, as we have seen, shows resumptive pronouns when a subject has moved non-locally, effectively singling out the embedded subject position. As a reviewer points out, this is similar in some extent to Swedish (Engdahl 1985: 8), where resumptives are used for just the subject position:

The use of resumptives for subjects only is a fairly common pattern across the languages of west Africa, and for further discussion to the issues discussed here, we refer the reader to Issah & Smith (in prep). It is then worthwhile questioning whether the same explanation that holds for Swedish can underpin Dagbani.

Engdahl proposes that resumptive pronouns in Swedish are phonetically realised wh-variables: that is, they are effectively the spell-out of a trace of movement. In contrast to a language like English, where a subject extraction from the position immediately after a complementiser is ungrammatical, movement from such a position is allowed in Swedish. Engdahl’s explantion is that the subject position is properly governed by C in Swedish. Furthermore, the language idiosyncratically requires that a trace in Spec,TP be realised phonetically (cf. Engdahl’s discussion of Norwegian, which is argued to have the same government of the embedded subject position, but phonetically empty variables there).

A reviewer points out, such an approach would circumvent the need for an antilocality explanation. Much as we appreciate the desire to find a common analysis for Dagbani and languages like Swedish, it is not the case that Dagbani can be seen as parallel to Swedish in this regard. In Dagbani, the use of the resumptive pronoun correlates with an ability to escape islands, but this is not the case in Swedish (Engdahl 1985). We do not see an easy way to handle this fact on the account where the resumptive is the spell-out of a trace, which is a notable drawback of movement-based theories of resumption (Salzmann 2017; 2018).

5.1 A movement analysis of local subject focus

Given that movement to Spec,CP is also not an option due to antilocality, we propose that Dagbani has been forced to innovate and has developed additional structure (for now, FP), with a higher projection above the one headed by ka.²⁰ If n fills the head position of this higher FP, then we arrive at the following structure, which we will revise immediately below.

In this structure, the specifier of the higher FP is sufficently far enough away from Spec,TP such that movement is now possible without violating Spec-to-Spec antilocality. There is a projection between Spec,TP and Spec,FP, namely CP, which is crossed with movement from Spec,TP, and antilocality is not violated. It should be further noted that fairly standard assumptions of economy, such as “shortest move” will restrict this position to matrix subjects. Since all other foci can move to Spec,CP, then they will do so. Local subjects, which are independently not allowed to do so because of antilocality, are only able to move to Spec,FP, and so that is where they move to. We propose that this is roughly the structure that arises for locally moved subjects. FP is generated only when necessary, and is forced to in the case of local subject foci, due to (i) the necessity of the subject to move to the left periphery to license its [uFocus] feature; (ii) a prolepsis derivation being unavailable due to the HSR; and (iii) antilocality preventing movement to Spec,CP. In the next subsection, we proceed to refine the structure further, to account for a couple of outstanding issues.

5.2 The difference between n and ka

Whilst (39) suffices to allow for movement of local subjects to the left-periphery, it is not quite sufficient for our purposes. Whilst the additional structure gives us the result we need, in order for the account to be insightful, we need to consider the composition of the head labelled F, as two pressing questions arise.

Firstly, positing a generic functional head F is not sufficient, and runs the risk of being a deus ex machina without further motivation. The subject moves to the left periphery in order to license its [uFoc] feature, and so in order for this to be successful, then F must carry [iFoc]. We could propose that Dagbani simply generates an extra phrase that carries focus above the CP that it already has. There would in essence be two focus phrases in the clause. However, despite this simplicity, Rizzi (1997) has argued that there is maximally one focus head per clause, which is in obvious conflict with a proposal where Dagbani generates another focus phrase on top of CP.²¹

We then propose that the CP is copied to an immediately dominating projection. That is, when the structure is being built, at the point that CP is inserted it is obvious to the derivation that it can no longer converge: C[iFoc] is too close to the element that bears [ufoc]. In order to save this, C[iFoc] is merged once more, which results in the following structure. Crucially, as will become clear in the discussion immediately below, this is not a case of head movement, and so the features on the lower copy are retained in addition to the higher ones. The subject can then move to the specifier of the higher CP, crossing the lower one and not violating antilocality.²²

This structure has the result that we can analyse why there are the two focus markers n and ka. We propose that n represents the spell-out of both Cs, either fused together as is often assumed in Distributed Morphology (Halle & Marantz 1993), or we have a case of a span spelling out two heads (Svenonius 2012; Merchant 2015; also Abels & Muriungi 2008), as in (41).²³ The rules in (42), are then part of the Dagbani lexicon.

Gereon Müller (p.c.) questions how, given that the two C-heads are featurally identical, the two rules in (42) could be distinguished for the purposes of Vocabulary Insertion (VI). We assume that VI is sensitive to the complexity of certain features, and as such, it can tell the difference between one instance of a feature and two instances of the same feature. There is some evidence that VI is sensitive to such things, particularly within the realm of case. Smith et al. (2015; 2019) argue that case features are internally complex and recursive, and that VI can distinguish between [K], which is the unmarked case of a language, say, nominative, and [KK], which would be the dependent case, say, accusative.²⁴

In light of this structure, one naturally wonders whether multiple foci are possible in Dagbani, and whether they give evidence for the two positions. However, multiple ex-situ foci are not possible in the same clause in Dagbani, and do not let us test the position of a focussed subject relative to a focussed object. Yet, the ban on multiple focus is interesting in the context of our proposed structure, and is worth some further discussion. In general, if two elements are in focus, one of the elements will move to the left-periphery and the other will stay in-situ. Furthermore, in environments where we would expect multiple wh-questions, only one of the elements is a wh-word, and the other is an indefinite.

We can see both of these as being the result of a general prohibition on multiple foci in Dagbani. Multiple foci are possible, as long as they appear in different clauses as in (44). Therefore, the ban on multiple foci seems to hold only per clause, as can be seen in the following, where both the matrix clauses and embedded clauses contain a question word, and are grammatical.

The obvious explanation for the ban on multiple ex-situ foci in a single clause is that there can be maximally one specifier of the CP. However, given that we have a shell-CP, with an intermediate position where there can be a specifier, one might expect then that an ex-situ object could occupy the lower specifier position. This does not happen, and deserves a little comment here. It is important to note though that we are not proposing that the higher CP is a second focus projection per sé. As a reviewer points out, Rizzi (1997) has suggested that there is maximally one focus projection per clause, though there is disagreement over this (Kiss 1998). Here, we are not proposing that there are multiple focus heads that bring in their own focus semantics. Rather, the expanded CP should be seen as a single instance of focus that is divided across multiple heads in the structure: that is, the higher C_[iFoc] is an extension of an existing one.²⁵ Thus, descriptively, we can say that the ban on multiple foci in the same clause comes from it being the case that [iFoc] can only be associated with one argument at a time.

In fact, there is some evidence that it is indeed the case that the two instances of C_[iFoc] work as a unit, and cannot each independently license a focus. For some speakers (2 out of 4 speakers consulted, including the first author of this paper), it is possible to have the following sentence, where both the embedded subject and embedded object are in focus, with the object moving to the matrix clause and the subject locally moving to the embedded left periphery:²⁶

Suppose that the two instances of [iFoc] in the embedded CP could independently license focus on different arguments, then under the assumptions here we would expect that the focussed object would move to the specifier of the lower CP, and no further, given that the trigger of movement — the need to value its unvalued [uFoc] feature — would be satisfied at that point. However, the embedded object does move higher, to the matrix left periphery. We propose that this happens because the two instances of [iFoc] in the embedded left periphery are the same feature (that is, the feature is shared across multiple heads in the tree, see Pesetsky & Torrego 2007; Abels 2012) and as such, whatever one of the instances is related to, the other is as well. As a collective, they then value the [uFoc] of the subject, but they cannot independently license different [uFoc] features. Since (the two instances of) [iFoc] can only be associated with one argument at a time, then the specifier position of the lower CP layer will not be a place where the embedded object can move to and value and license its [uFoc]. Thus, in (45), the embedded subject moves to the specifier of the embedded CP, where its [uFoc] is valued and licensed by the [iFoc] that is shared across the two CP heads. This [iFoc] feature cannot then license any other foci. This means that the embedded object must move into the matrix left periphery, in order to find a C_[iFoc] that is unassociated with any other focussed argument. We assume that the embedded object moves through the specifier of the projection hosting nì, which we take to be the CP head that is the equivalent to the cartographic ForceP, labelled as C_ForceP.²⁷ The derivation is given below, with irrelevant projections removed:

As a final point before leaving this discussion, a reviewer questions why the expansion of CP does not apply in embedded clauses, allowing embedded subjects to move to the matrix clause without having to make use of the resumptive pronoun.²⁸ That is, what is there to stop the following:

If such a derivation would exist, then we would expect an embedded subject to move into the matrix left periphery, but not leave a resumptive pronoun in the lower clause. Given that we do not find such sentences, then we can be confident that the derivation does not exist. However, the question is why. The best speculation that we can give to this is that copying the C head is a marked option (potentially instructive as to why Dagbani type languages with two focus markers appear to be quite uncommon). The copying of CP happens only as a last resort option, when nothing else will let the derivation converge. The option of using prolepsis for subjects in embedded clauses could mean that there is nothing to force the iteration of the embedded CP. That is, it is in some sense more economical to use prolepsis than making the complex CP that is needed to allow an embedded subject to extract. One could handle this in terms of OT-style ranked constraints, broadly along the lines of Salzmann (2013). Unfortunately, due to space restrictions we cannot explore this any further here. However, we refer the reader to Issah & Smith (in prep) where we discuss constraint violations of these types in further detail across a larger sample of west African languages.

6.1 C-T Bundling

The C-T bundling approach proposes that C and T together form a complex head, which following convention in the cited works we call CT. The idea in brief is as follows: since subjects seem to have difficulty moving from Spec,TP to Spec,CP (whether this is due to antilocality or some other constraint is orthoganol to the current point), then a language can bundle the heads C and T onto the same node, and this head can fulfill the requirements of both the C and the T with the same argument in the same position, namely in its specifier. Such a head will be responsible for the EPP, as well as information structural related movements in the language. We first illustrate this in more detail, before discussing why we do not believe that it is applicable to Dagbani.

6.2 n as a marker of in-situ focus

Another possibility suggesting to us by Michael Yoshitaka Erlewine (p.c.) is that n is not a head in the left periphery at all, but rather is a marker of foci that are in-situ. Recall that we have proposed throughout this paper that n is a variant of the C head that encodes focus, essentially n and ka are allomorphs (see section 6.3. However, it is very hard to diagnose this, given that subjects are usually left-most in the sentence to begin with, and movement to the left-periphery is string vacuous. This leaves open the possibility that subjects simply remain in-situ, and look as though they have been moved to the left-periphery. An option then, would be to anlayse n as a marker of arguments that are in focus, but also in-situ.

It is clear however, that this is not its function. It is easy to show that in-situ focus is allowed for any element that is not a subject in Dagbani. We showed this above in (16), repeated below.

(54-b) is a congruent answer to the question in (54-a). As shown, it is not obligatory to mark the object with n. The marker lá can — but need not — appear, but crucially n can never appear. What the data show then, is that elements that are clearly in-situ foci — clearly shown given their lack of movement to the left-periphery — are not marked by n.

This does not of course prove that subjects are not in focus. n could then be a marker of in-situ subject foci. However, the mechanics of getting such an approach to work are tricky. One possibility for this is that the head of the projection which hosts the subject is canonically null, but is realised as n when the subject is in focus. Recall from the previous subsection that given the independence of n and tense, then the projection cannot be assumed to be T. Thus, we would need to assume some projection specific to the subject, such as SubjP Rizzi & Shlonsky (2007); Bennet, Akinlabi & Connell (2012). However, there is no evidence that we can find, direct or indirect, that can point us towards the existence of a SubjP. Furthermore, n and ka are in complementary distribution, and serve by and large the same functions, and it seems simpler to us to assume that n, along with ka is the realisation of a focus head in the left-periphery. It should be stressed that if one were inclined, it is possible to analyse n as the realisation of Subj when a DP carrying a focus interpretation occupies its specifier. We have stated that there is no reason to believe that this is the case, but it is difficult to prove the non-existence of SubjP, and an associated sensitivity of Subj to focus. The point is that this is at best no less stipulative than our analysis, and raises important questions about how much information regarding grammatical roles is needed to be visible to the syntax.

6.3 n as an exceptional licensor of nominative case

If we are right, and it is the case that both n and ka are both C heads, then they are allomorphs of one another. As we have discussed above, we believe that this conclusion is correct, that n represents the realisation of C, albeit more structurally complex than ka. However, if both n and ka are C-heads, it is not the only way that this could be the case.

Another option, also suggested to us by Michael Yoshitaka Erlewine and an anonymous reviewer, is that n and ka are realisations of the same head, but they are not structurally different. Rather, the difference between the two is that n is a C head that is exceptionally able to assign nominative case. There is no complex C head in the case of n, but due to the ability to n to license nominative case, the subject can bypass Spec,TP and move there directly. The use of n in this sense can still be seen as an option of last resort in the sense that it would be only used when necessary, i.e. when it is needed to license nominative case, and that in doing so, nominatives are freed from the need to land in Spec,TP. Were we to assume that nominative is (a) necessary for subjects; and (b) only able to be assigned in Spec,TP — both assumptions that have been explored extensively in the history of the field — then any subject that skips Spec,TP will not recieve nominative case. Suppose then that antilocality remains, and prevents movement between Spec,TP and Spec,CP, then a subject that is in focus can as a last resort move directly to Spec,CP to satisfy a focus requirement, yet still be case licensed through the use of n, which assigns nominative (indicated by subscript NOM in (55)) as well as performing its usual information structure duties.

Since n is used only where necessary, then other foci (objects, adjuncts and non-local subjects) would use ka, and nominative would be assigned by T in the normal way (as above, the assigner of nominative case is indicated by NOM).

Though this approach works from a technical perspective we feel like there are two principal problems that lead us to believe that it is not the right approach. First is the notion that n is a last-resort assigner of nominative case to the subject. As in many languages of the region, morphological case is only a peripheral phenomenon in Dagbani. Lexical nouns do not show case alternations, and so case is only seen in (a subset of) the pronouns. Yet, despite there being a set of pronouns for nominative case, these are never found when a pronoun is a focus. Rather, the emphatic pronouns must be used, which do not show any case alternations.

This is not a surprising result: it is not uncommon for languages to require a strong form of a pronoun in a position where said pronoun is prominent (Cardinaletti & Starke 1999). However it does cast considerable doubt on the claim that n is a licensor of nominative case, given that the nominative specific pronouns are disallowed from appearing with it. Thus, there is no evidence to support this account.

A further problem is with the assumption that n would allow the subject to bypass Spec,TP. Given the assumption that the subject can in principle avoid moving to Spec,TP when focussed, we would expect that this should be available also for embedded subjects. For instance, the embedded subject should be able to move directly from Spec,vP in the embedded clause to the embedded Spec,CP, and then onto the matrix left-periphery.³² Since it can be licensed with nominative case in the final landing site by n, there is no reason for it to stop in the lower Spec,TP. Yet, there is evidence that this derivation is not available given that a resumptive pronoun must be used in a non-local Spec,TP. There is clearly something that ensures that the subject, or something linked to it, moves to Spec,TP and it is not possible to avoid this.

6.4 Summary

In this section we have explored three alternatives to our treatment of the focus marker n. We have seen that there is empirical evidence against the first two of these, namely that n would be a bundle of C and T, or that n is a marker of in-situ focus. We have also not been able to find evidence in favour of the latter approach whereby n allows the subject to bypass Spec,TP by licensing nominative case on the subject, and that there is suggestive evidence against it. Furthermore, even on the last approach, which we are unable to conclusively discount, other aspects of ex-situ focus constructions remain and independent mechanisms must be additionally posited.