2.1 Greek RCs

RCs of different kinds (restrictive, non-restrictive or pseudo-relatives) and embedded clauses after emotive factive predicates are introduced by the complementizer pu in Greek. Sentence (6a) below is a SRC and (6b) is an ORC.

DPs are marked with case (nominative or accusative in subject and object positions respectively) and gender morphology (masculine, feminine, or neuter), overtly expressed both on the determiner and the noun.⁵ Unlike nominals, verbs are not inflected for gender, hence, Greek is unlike Hebrew in this respect, and like Italian, indicating that gender is not a syntactically active feature in the relevant sense in Greek.

A-bar movement e.g., wh-, focus movement or relativization of an object across a subject triggers subject inversion, hence, the subject surfaces post-verbally in (7)–(8). The consensus in previous literature about the position of inverted subjects in wh-questions is that they are in a VP-internal position (cf. Anagnostopoulou 1994; Kotzoglou 2006).⁶ We assume that inverted subjects are no different in RCs, therefore they occupy a VP-internal position, which counts as an intervening one for the movement dependency established in ORCs, (9).

2.2 The participants

18 right handed individuals participated in the study to be reported, all native speakers of Greek. 6 of them were non-fluent Broca’s aphasics, (Ps), and 12 constituted their control group, (Cs). There were two control participants for each aphasic, matched for age, gender and education. The participants with Broca’s aphasia were assessed via the Greek version of the Boston Aphasia Battery (Papathanasiou et al. 2008). Aspects of this assessment appear in Table 1, along with additional characteristics that make up the aphasic participants’ profile.

All aphasic participants were diagnosed as non-fluent Broca’s aphasics (agrammatics) by an experienced speech-language pathologist on the basis of their spontaneous speech, which consisted of short and simple sentences, with verbs almost exclusively in the present tense, and some omission of determiners. Their spontaneous speech samples, based on the Cookie Theft story, appear in the Appendix.

2.3 The materials

A number of language tasks were administered to the participants, in addition to the RC tasks that are the focus of the present study and will be presented in detail in the following section. These were: a) a Past Tense/Reference elicitation task, b) an object clitics elicitation task, c) two comprehension tasks of passive sentences (short and long passives).⁷ For the purposes of a different project (see Nerantzini et al. 2015), the aphasic participants were also assessed on their mastery of case morphology. The tasks were administered in three or four sessions within a week.

3.1 Results

The results of Study I appear in Table 2. This Table also contains the results of the aphasic group on the active transitive sentences of the task, and those of the control participants on SRCs and ORCs together.

As one may observe, there is a significant difference between the overall performance of the aphasic participants on ORCs and SRCs. Whereas more than 41% of the participants appear to regularly struggle with ORCs, the respective error rate for SRCs is slightly higher than 11%. The difference is statistically significant (paired t-test, t(5) = –11.931, p < 0.001) and is further supported by the fact that the error rate on active sentences is much lower. In fact, only 2 errors were observed in sentences with two DP arguments such as ‘Here the grandmother photographs the groom’, which amounts to an error rate of 1.4%, indicating that the aphasic participants had no problem with the task per se.

A more analytical drill-down of the ORCs across the gender distinction revealed another statistically significant difference, at the 5% level (paired t-test, t(5) = 2.666, p < 0.05). The error rate on ORCs with DPs that have the same value for the feature gender (ORCs – match) is 54.2%, while of the ORCs with DPs of different gender (ORCs – mismatch) is only 29.2%. It should be pointed out that although participants were presented with three pictures to choose from, chance level was not at 33% since they almost never picked the distractor picture. Finally, the error rate of the healthy controls was 0.7% for SRCs and 2% for ORCs and because it was so low we did not analyze their results any further.

Some first conclusions to draw therefore are that: a) ORCs do indeed create a much bigger problem than SRCs for the Greek-speaking agrammatics, and b) same value for the feature gender constitutes an additional source of difficulty for the comprehension of ORCs. Such an effect of the feature gender has been reported, but in studies of immature grammar/child language, cf. Belletti et al. (2012). The current findings suggest at first glance that the gender feature plays a similar role in the language of the Greek-speaking individuals with Broca’s aphasia.

A closer look at the details of the experiment, however, reveal two factors that have to be given a second thought before settling with the findings just reported. These are factors that may have rendered ORCs more difficult than what they actually are, hence, may have rendered the difference between ORCs and SRCs more pronounced, but for reasons other than the intervention effects that we are investigating. As a consequence, the effect of gender may have been more pronounced as well. Recall that the experimenter introduced the sentences with the phrase ‘here is …’, (10). If one introduces a sentence in this manner, the DP that follows the introduction must bear nominative case. This is fine for SRCs, because the first DP of the sentence is the subject with the agent thematic role, and it typically bears nominative case in a language such as Greek. It may not be fine for ORCs, however, since the first DP, which corresponds to the relativized object, also bears nominative case, despite the fact that it starts out with accusative and it is the DP with the patient thematic role. This case discrepancy between the relativized element in its surface vs. underlying positions, which is an outcome of the manner in which the experiment is administered, may pose an additional difficulty for ORCs. Because case morphology is often considered to assist in figuring out grammatical functions/thematic roles, see, for instance, Stavrakaki et al. (2015) for typically developing Greek-speaking children, it may be that it creates additional difficulties for the ORCs of this task and it blurs the results.

This is not the only difficulty that may arise for ORCs. Notice that the second DP of ORCs bears nominative, which looks all right, because it is the subject of the sentence and the DP with the agent thematic role. However, taken together with the first DP, it results in that both DPs bear the same (nominative) case in a task that assesses ORCs. This by itself may constitute an additional reason why ORCs are more demanding than subject SRCs in the overall: case morphology, which is distinct and overt in Greek, may be involved in the computation of similarity between the moved object and the intervening subject and induce additional difficulties in ORCs. It should be clarified that case has not been considered as one of the morphosyntactic features involved in the computation of similarity in the relevant sense (Rizzi 2004; Grillo 2009). Nevertheless, one would probably not want to exclude such a possibility, especially because it had not been tested experimentally before the current study was undertaken (and see also footnote 10).

To sum up, although the agrammatics of the current study performed clearly different on SRCs and ORCs, with much lower scores on the latter, it is conceivable that the ORCs turned out more difficult for reasons other than those that have standardly been taken to explain the difficulties they pose in agrammatism within a RM approach. They are reasons that have to do with the particular morphosyntactic features of the DPs in the language(s) under investigation, and how these interact with the manner in which the sentences are administered. They may arise in a paradigm such as the one at hand when a) the two DPs of ORCs end up with the same case feature, and b) there is no mapping between case and thematic roles of the type expected in the active sentences of a Nominative language such as Greek, that is, accusative for the object with the patient thematic role and nominative case for the subject with the agent thematic role. We thought that these are potential confounds that should not be overlooked and one should not settle with the results of an experiment that contains them.

4.1 Results

The results of Study II appear in Table 3. A quick look at it leaves us with the impression that performance has not changed in important ways from that in Study I.

The results in Table 3 are in accordance with the findings of Study I in many ways. Again, the observed difference between SRCs (15.3% error rate) and ORCs (46.5% error rate) is statistically significant at the 0.001 level (paired t-test, t(5) = –17.516, p < 0.001). Healthy controls had similarly low error rates, that is, 1% on SRCs and 0.7% on ORCs.

Importantly, even in this task there is a serious and statistically significant gap in performance on ORCs whose DPs have the same value for gender and those that do not, that is, an error rate of 59.7% vs. 33.3% respectively (t(5) = 4.503, p < 0.01).

Let us now turn to the effects of case that the two experiments reveal. The hypothesized additional difficulty on the SRCs of Study II, assumed to be induced by the fact that the relativized subject with the agent thematic role bears accusative case, indeed amounts to lower performance. The error rate on SRCs this time is higher when compared to the error rate of Study I, i.e., 15.27% vs. 11.11%, although the difference does not reach significance (t(5) = –1.936, p = 0.11). We consider this finding to indicate that when morphological case does not assist in figuring out the thematic role of a DP, in particular, when an agent subject has an accusative case feature, this may have a negative effect on the comprehension of a SRC in agrammatism, the extend of which has to be further confirmed.

Turning to ORCs, we are faced with an unexpected finding. Recall that Study II was designed so that ORCs in particular be void of difficulties that are independent of the aims of the investigation. Yet, a higher error rate emerged, namely, 46.5% (vs. 41.7% in Study I). The difference is not enormous, yet, it reaches significance (t(5) = –3796, p < 0.05). It is difficult to tell what the source of the lower performance on ORCs of Study II is, especially because the task was created with the expectation of similar, if not better, performance. What we can probably tell, however, is that lack of mapping between case and thematic role in this particular direction, that is, nominative for object DPs, does not pose difficulties in agrammatism. Most importantly, we can also claim with certainty that same value for the feature case of the two DPs participating in ORCs does not induce minimality effects, as there was no improved performance whatsoever on the ORCs of Study II, in which the two DPs had a different value for case. In other words, by contrast to gender, case morphology does not seem to play a role in the computation of similarity between a moved DP and an intervening one for Greek-speaking agrammatics. We will return to these novel findings in the Discussion section.⁸

5.1 The role of case

Recall that one of the reasons that called into question the results of Study I was the fact that the two DPs of ORCs ended up having the same value (nominative) for the feature case. We became concerned, therefore, that ORCs were rendered even more difficult precisely for this reason, despite the fact that case features have not been considered to enter into the computation of locality by the RM based accounts we have discussed.¹⁰ Nevertheless, case features had not been investigated for minimality effects in early or atypical language, at least not until the research reported here was undertaken.

Comparing the performance on the ORCs of Study I and Study II offered the opportunity to investigate whether the morphosyntactic feature case is involved in computing locality and inducing intervention effects. If case were such a feature, one would expect Study II to give a lower error rate for ORCs than Study I, because the two DPs do not have the same value for case. This is not what we obtained however: by contrast, the error rate was 46.5% in Study II, while it was 41.7% in Study I. Although we are not in position to explain the higher error rate in Study II, the finding leads us to conclude with certainty that structural case is by no means one of the features of DPs that may induce intervention effects in agrammatism. Therefore, it is correctly left out by the featural RM approach to understanding developing language systems or systems affected by pathologies.

Interestingly, a study that appeared during the submission process of this paper reached similar conclusions with respect to the intervention effects of the structural case of DPs. Friednmann et al. (2016) examined a number of populations, including agrammatics, on object wh-questions and object topicalization, by manipulating the object marker et in Hebrew, and concluded that overt case marking cannot rescue a structure that builds a movement chain over an intervener. The study we are reporting here offers further support via Greek, which is a language with overt case marking as well, but different from that of Hebrew, in the sense that the different values of case are manifested on both the determiner and the noun, and DPs always have an overtly expressed value for case.

It is important to note that this aspect of the behavior of the aphasic participants cannot possibly be attributed to problems they may have with structural case, a well-known weakness in agrammatism, as amply demonstrated by Ruigendijk & Bastiaanse (2002) and Ruigendijk & Friednmann (2008), among others. In other words, one cannot possibly claim that the aphasics of our study did not differentiate between ORCs with DPs that bear the same case feature and those that do not because they cannot tell the morphological instantiation of the different values of the feature case. We know this because we ran a set of experiments on case, as part of a different project, see Nerantzini et al. (2015), in which the aphasics of the current study participated as well and were found to have close to ceiling performance on a judgement and a production task of nominative and accusative case.

Before closing this section, let us draw attention to the other case related issue raised in this work. In section 3.1.1 we first expressed the concern whether lack of mapping between a particular thematic role and a particular value of the feature case may have posed additional difficulties on the ORCs of Study I, raising at the same time the question of whether overt morphological case assists in recovering grammatical functions in agrammatism, an issue that is independent of the potential minimality effects of case.¹¹ We found that subjects/agents with an accusative case feature render SRCs harder, the extent to which is not clear, as results did not reach statistical significance and should probably be replicated, but they are to the expected direction.¹² On the other hand, objects/patients with nominative case did not render ORCs more difficult; if anything, we found the opposite effect. This discrepancy regarding the role of morphological case in assisting identification of thematic roles may be related to the fact that DPs with nominative case and patient thematic role are abundant in the language, as subjects of unaccusatives or passives, for instance. On the other hand, no agents with accusative case are to be encountered in any syntactic environment, hence, the difficulties on the SRCs of Study II.

5.2 The role of gender

We left for last what is a focal aspect of this study, that is, the impact of gender features on the comprehension of ORCs. Investigating gender features in this context is important for a number of reasons. First, it is a feature that has not been studied in terms of its impact on the computation of A’-dependencies in agrammatism, neither in Greek, nor crosslinguistically. Moreover, it is not a feature that is associated with the left periphery, hence, potential difficulties cannot be attributed to the well-known impaired left periphery in agrammatism (Friednmann & Grodzinsky 1997).

Most importantly, however, it is a feature that has led to important claims regarding an accurate classification of the morphosyntactic features that may induce intervention effects, albeit on the basis of child language. It has been repeated several times already, that, after comparing Italian- and Hebrew-speaking children’s ORCs, Belletti et al. (2012) concluded that gender has this ability in Hebrew, but not in Italian, because only in Hebrew is it a syntactically active feature. As has been amply demonstrated here, however, same gender features do induce additional strains on the ORCs of Greek-speaking agrammatics. This is surprising, as gender cannot be considered an active feature in Greek in any obvious manner. For one thing, Greek verbs are not inflected for gender.

We are led to consider a number of factors as potentially responsible for this unexpected finding. One may think that the results of the Italian children reported in Belletti et al. (2012) constitute an accident. Besides being the less interesting approach to the puzzle, this is not right on factual grounds. Similar results were obtained even earlier, by Adani et al. (2010), for Italian-speaking children. Moreover, the interpretation Adani et al. offer is not much different: the authors argue that external and syntactically active features, such as number, induce intervention effects, while internal and (possibly) lexicalized features, like gender, do not. Notice, furthermore, that the type of DPs the two studies employ in their experiments are rather different. While Belletti et al. employ DPs similar to ours, that is, DPs in which grammatical gender largely corresponds to natural gender, the Adani et al. study mostly employs DPs that refer to animals, for which no such direct correspondence holds. Yet, both studies obtain similar results on gender (and number) of the Italian-speaking children, a convergence that cannot be accidental.

Another possibility is that Belletti et al. (2012) were not right about gender acting as it does in Hebrew as a consequence of being syntactically active. Alternatively, it may be that not only syntactically active features in the sense of Belletti et al. are able to induce intervention effects, but also other properties of gender may be relevant for minimality. Greek has, for instance, a tripartite distinction of gender (masculine, feminine, neuter), by contrast to Hebrew and Italian, and gender is marked on both the determiner and the noun, by contrast to Hebrew.

A yet conceivable possibility is that one should not necessarily expect intervention effects of the type we have discussed to operate in adult impaired grammar, just because this happens to be the case in other domains of child and agrammatic language. It may be that features that are not syntactically active crosslinguistically facilitate or pose additional strains in agrammatism, in a way that does not hold for immature grammar, raising of course the question whether these are effects that can be captured via a RM/grammar based approach. Unfortunately, there are no studies of Italian agrammatics on the intervention effects of gender. Likewise, there have been no studies of Greek-speaking children on the role of gender in computing locality. If there were, and it was found that children behaved like agrammatics, one would either entertain the idea that the morphosyntactic feature gender is different in Greek, in ways that have to be investigated along the lines of the previous paragraph, or that the RM approach to intervention effects that associates only syntactically active features with locality and intervention is not on the right track. These are clearly way too many open issues to allow for a valuable conclusion regarding the effects of gender we have reported in the grammar of the Greek-speaking agrammatics. A manner to narrow them down is by investigating the behavior of Greek-speaking children on gender in ORCs, hence eliminate the last open issue.

5.3 Greek immature RCs: The answer to the puzzle

In Angelopoulos & Terzi (2017) 15 Greek-speaking children age 4;1–5;2 (mean age: 4;9) were administered the very same RC tasks that were administered to the agrammatic participants. We report here the results of SRCs from Study I and of ORCs from Study II, for the reasons we have explained in footnote 12. Children did significantly better on SRCs than on ORCs (20.5% vs. 4.7% error rate respectively, t(14) = –8.218, p < 0.001), but there was no difference within ORCs depending on whether the two DPs had the same or different value for the feature gender (21.1% vs. 20% respectively, t(14) = 1.418, p = 0.158). Because children’s error rate on ORCs was not particularly high, and certainly much lower than the error rate of the agrammatics we studied, we wanted to exclude the possibility that children’s grammar was approaching adult typical grammar, a state of affairs which is expected to minimize the intervention effects under investigation. In order to factor out this possibility we divided the children in two age groups, below and above age 4;6. The younger children (mean age: 4;4) had much higher error rates on both ORCs and SRCs (40.0% vs. 6.8% respectively, t(4) = –7.14, p < 0.001). The error rate of the younger children on ORCs was in fact very close to that of the agrammatics we have reported (46.5%). Still, even the younger children of the group did not differ in terms of whether the two DPs of ORCs had the same or different value for the feature gender (41.7% vs. 38.3% error rate respectively, t(4) = 1.426, p = 0.159).

The study of Greek-speaking children’s RCs revealed, therefore, that gender does not induce minimality effects in the immature Greek grammar. This is an expected finding under the claim that difficulties with ORCs which are the result of intervention effects in immature grammars are induced by syntactically active features (Belletti et al. 2012), along with the fact that gender is not a syntactically active feature in Greek in the relevant sense, i.e., a feature associated with syntactic movement of the DP. At the same time the finding confirms that, since gender behaves as expected under the above premises, no further investigation is necessary in quest of specific properties it may have in Greek in order to understand its unexpected effects in agrammatism. If there was something particular about the morphosyntactic feature gender in Greek, potentially responsible for the difficulties induced in the match conditions of ORCs in agrammatism, this would presumably carry over to immature grammar. However, our study of Greek-speaking children demonstrated that it doesn’t.

We should, therefore, focus on other aspects of the language of agrammatics in order to understand the effects of gender on ORCs. We argue that these effects are not explicitly anchored to some specific principle of syntactic locality in the case of the agrammatics of the current study, and perhaps of agrammatics crosslinguistically, despite the fact that they look like RM effects. Alternatively put, we believe that, although the performance of the agrammatics we tested on RCs seem to follow from an extension of RM to language pathology (see Rizzi 2013 for a related view), this is actually not the case, at least not for a phi-feature such as gender. Our view seems to be on the right track on both conceptual and empirical grounds. Conceptually, because there is no possible ground on which gender can be considered an active moprphosyntactic feature in Greek, along the lines of Belletti et al. (2012 et seq.), a view that was actually confirmed by the ORCs of Greek-speaking children. Empirically, because, if the similarity effects of gender on the ORCs of agrammatics were effects of syntactic locality and intervention of the type RM is about, one would not expect to find them in other domains as well.

It turns out that we find them, however. Very similar effects of gender hold for the SRCs of the agrammatics we tested, despite the fact that no intervention configuration whatsoever is present, namely, nothing intervenes between the relativized subject, o kirios ‘the man’ and the extraction site at which it is interpreted, as demonstrated by the SRC in (10a), repeated slightly modified for reasons of exposition below:

The SRCs results of Study I in Table 2 demonstrate that the overall error rate on SRCs is 11.1%, a much lower error rate than on ORCs. What we also see in Table 2, however, is that for those SRCs whose two DPs have the same value for the feature gender (SRC-match condition) the error rate is 19.4%, while it drops drastically to 2.8% for the subject RCs whose DPs have a different value for gender (SRC-mismatch condition). This difference is statistically significant (t(5) = 3.873, p < 0.05), and by no means does it fall under RM intervention effects.¹³

To recap, the sharp effect that the morphosyntactic feature gender was found to have on the ORCs of Greek-speaking agrammatics raised serious questions as to whether associating it with a specific principle of syntactic locality, namely, RM, is on the right track for understanding language pathology. This is so because of the very precise views RM holds about the properties of the morphosyntactic features that may induce intervention effects, which do not characterize the feature gender in Greek. Closer investigation of the effects of gender in: a) immature Greek grammar and b) the SRCs of the same group of Greek-speaking agrammatics, led us to conclude that the behavior of agrammatics on ORCs, although much reminiscent of RM effects, actually falls outside their scope. We are led to believe that this is the case for agrammatism when it comes to morphosyntactic features that are not related to the left periphery of the sentence, a domain of grammar that is known to be particularly vulnerable in agrammatism and has been accounted for via RM since Grillo (2008). Gender is precisely such a feature.¹⁴ At the same time, the idea of relating difficulties with ORCs to a syntactic locality principle such as RM, which seemed seriously undermined by the findings of Greek-speaking agrammatics, because of the status of gender in the language, turned out not to be challenged. In other words, the claims of RM as to which features may be implicated in computing locality, namely, active morphosyntactic features, continues to be valid, but for early grammar. As for adult impaired grammar, with agrammatism being a core case of it, although this may be so for morphosyntactic features involving the left periphery, it does not seem to hold for phi-features.