We carried out three experiments aiming at examining how French-speaking children as well as French- and Italian-speaking adults understand and process relative clauses. In particular, we were interested in the relative difficulty in the processing and acquisition of OSV and OVS relatives in these two languages. Our starting points were (i) the generalization that structures that are more difficult to process for adults are mastered later by children (
Phillips and Ehrenhofer 2015), and (ii) the findings by
Schelstraete and Degand (
1998) that French-speaking adults process OVS object relative clauses more easily than OSV ones. The authors took their finding as evidence for an approach of relative clause processing in terms of the competition model, according to which the processing of OSV should be harder due to higher memory costs. Specifically, they claimed that OSV RCs are harder than OVS because two arguments have to be kept in memory before the verb is reached (
Bates and MacWhinney 1987). In contrast, our results from three experiments all point to a greater difficulty in the processing (adults) or comprehension (children) of OVS compared to OSV relatives. This finding was consistently found in 6;5 year-old French-speaking children and in French- and Italian-speaking adults and replicates what was previously established for Italian-speaking children in several studies using different tasks (
Adani 2011;
Arosio et al. 2009;
Arosio et al. 2012). We argued that the conclusions by
Schelstraete and Degand (
1998) were based on the fact that (1) they compared smaller segments, involving only the verb, that critically differed in their position in OSV and OVS sentences, and (2) they focused on only one aspect of their results, namely reading times at the verb (longer for OSV than OVS), neglecting another aspect, reading times at the subject, which pointed to the opposite direction (longer reading times for OVS than for OSV). By measuring reading times on a wider segment including both the verb and the subject (preverbal in OSV, postverbal in OVS), as we did here, we were able to overcome the problem of comparing different segments and capitalize on an overall measure of difficulty for the two object RCs. This led us to conclude that OVS sentences are globally harder to process than OSV sentences.
Our finding that OSV ORCs are easier to process than OVS ORCs does not align with the prediction of the competition model. The fact that it is observed for both children and adults, of both French and Italian, together with the well-established finding that both children and adults struggle with object relatives more than with subject relatives, suggests that common explanatory factors underlie both OSV and OVS relative clause processing in the two age groups. What are these factors? Our data support a parsing account whereby the parser prefers to assign a subject relative clause analysis (Minimal Chain Principle,
De Vincenzi 1991). That is, at the relative head, the subject role is assigned to the relative head (as this involves the shortest dependency). This analysis is abandoned and revision must start, when some material incongruent with the preferred analysis is encountered. This is the embedded subject in OSV relatives, and the embedded verb in OVS relatives.
4 The revision process is modulated by the mode of disambiguation or the type of information encountered. Following
Fodor and Inoue’s (
2000) diagnosis model (see also
Bader and Meng 1999;
Arosio et al. 2009), we propose that OSV relatives are easier to process than OVS relatives because, whereas the former ones involve positive information as to how the initial parse has to be revised, the latter does not. In OSV relatives, the subject, situated in the preverbal canonical subject position, informs the parser that a subject RC analysis is not correct and it also indicates what expression must be the subject: the preverbal NP itself. The additional time needed to process this structure, as compared to subject relatives, is the time needed to reassign the thematic role of the subject (see also
Frauenfelder et al. 1980). The processing cost observed by
Schelstraete and Degand (
1998) at the verb in OSV may reflect a spillover effect of the reanalysis initiated at the subject of the relative clause. In OVS, instead, the information that comes after the first noun phrase (despite the complementizer) is the verb. Here, verbal agreement provides information for reanalysis, if the verb fails to agree with the initial NP. In that case, the information comes in a negative form: it tells the parser that the relative head is not the subject, but it does not tell the parser what expression the subject is. The parser must look for a subject in this case. In other words, the parser knows that the analysis is wrong, but no information is provided about how to repair the initial parse. It is only at the postverbal NP that the parser can engage in reanalysis: if that NP agrees with the verb, it can be analyzed as its subject, and the relative head can thus be reanalyzed as the object. In other words, parsing is doubly difficult in OVS: on the one hand, the parser is left without a solution at the verb (while it has a solution at the preverbal subject, i.e., at the point, which triggers reanalysis); on the other, when a solution is found, an additional operation of agreement checking has to be performed. The fact that
Schelstraete and Degand (
1998) found a processing cost at the postverbal subject in OVS may reflect the fact that only when the subject is found the parser engages in a new analysis. Under this view, the course of acquisition could be explained by assuming that children also start with the simpler analysis, that of subject RCs. It is known that at young ages, children are reluctant to abandon a preferred response, i.e., they have weak inhibitory skills (
Mazuka et al. 2009;
Choi and Trueswell 2010). Hence, their overall difficulty with object RCs may be due to a difficulty to engage in a revision process. As they grow older, they may be better equipped to abandon the subject RC analysis, because inhibitory skills have improved. The higher difficulty they show with OVS structures may be due to the negative nature of the information that leads to the revision. This view is congruent with results from
Guasti et al. (
2012b) on Greek and by
Arosio et al. (
2012) on German for children and by
Meng and Bader (
2000) for adult German. We illustrate this point by relaying on Greek.
Guasti et al. (
2012b) investigated children’s comprehension of subject and OVS RCs in Greek, a language that can mark nominal elements with morphological case (as German). Two types of OVS RCs were tested, illustrated in (8):
8. | a. | Dhikse | mou | To | alogo | pou | kinigoun | ta | liontaria |
| | Show | me | the.neut.sg | horse | that | pull.3pl | the.neut.pl | lion |
| | ‘Show me the horse that the lions are pulling.’ | | |
| | | | | | | | | |
| b. | Dhikse | mou | ti | maimou | pou | pleni | I | arkouda |
| | Show | me | the.acc.fem.sg | monkey | that | wash.3sg | the.nom.fem.sg | bear |
| | ‘Show me the monkey that the bear is washing.’ | | |
| | | | | | | | | | | |
(8a) is like the OVS RC that we tested in French and Italian: the two nouns are marked with neuter case (specifically on the article), which is compatible with a subject or an object role. The information that indicates that the sentence is an object RC is verbal agreement: the verb does not agree with the relative head. This is a piece of negative information. (8b), instead, has the relative head morphologically marked with accusative case and the postverbal NP marked with nominative case. This information provides positive evidence that the preverbal NP is the object (it has accusative case) and the postverbal NP is the subject (it has nominative case).
Guasti et al. (
2012b) found that 5-year-old Greek-speaking children were better at comprehending subject than OVS RCs, as in Italian. In addition, they found that the same children comprehended OVS RCs as in (8b) better than OVS RCs as in (8a). The fact that subject RCs are easier indicates that children engage in a subject RC analysis (even if the relative head is marked accusative case (by the main verb). The difference between the two types of OVS RCs can be explained if we assume that morphological case is a positive piece of information that tells the parser who the subject and object are, while verbal agreement is a negative piece of information, that signal that the preferred subject relative clause analysis is wrong, but still requires the parser to find the subject and check agreement. On a similar vein,
Meng and Bader (
2000), based on German, found that adults are quicker at revising wh-questions disambiguated by morphological case than those disambiguated by agreement. Notice that this fact further supports our generalization (2), in that it also shows that children and adults are similarly affected by the type of information that disambiguate a given sentence.
So far, we have capitalized on the similarities between Italian and French RCs. However, there is one relevant difference. The complementizer in French RCs tells one whether a subject or an object RCs is to be expected. If this piece of information would immediately have been taken into account, we should not have observed a subject/object asymmetry. Whether or not they did at some point, we cannot tell on the basis of our data.
5 In any event, the finding that even adults still struggle with object relatives in French suggests that the information provided by the complementizer is actually not, or only weakly, taken into account. One reviewer notices that the reading times are generally higher all over the segments in Italian than in French and wonders whether this depends on the fact that, in French, the complementizer signals what type of relative clause is to be expected. We cannot exclude this, but we find it unlikely that the different reading times depend on the different nature of the complementizers in the two languages, because reading times are already shorter in French, at the first NP before the complementizer. In order to find out if and how the information concerning the complementizer is used by the parser, we would need to carry out an experiment with German relatives and manipulate the information on the complementizer. In (9a), the complementizer
den (‘that’+ACC) indicates that the relative head is an object. In (9b), the complementizer
das (‘that’+NEUTER) can be nominative or accusative. It is only at the embedded subject
den Mann that the sentence is disambiguated. If the information on the complementizer is immediately used, (9a) should be easier or elicit shorter reaction time than (9b).
9. | a. | Zeig | mir | den | Mann, | den | am Montag | das | Kind |
| | Show | me | the.acc | man | that. acc | on Monday | the.neuter | child |
| | getroffen hat | | | | | | |
| | found has | | | | | | |
| | ‘Show me the man that the child found on Monday.’ |
| | |
| b. | Zeig | mir | das | Kind, | das | am Montag | der | Mann |
| | Show | me | the.neuter | Child | that.neuter | on Monday | the.nom | man |
| | getroffen hat | | | | | | |
| | found has | | | | | | |
| | ‘Show me the child that the man found on Monday.’ | | |
| | | | | | | | | | | | | |
In conclusion, we have shown that French- and Italian-speaking children and adults behave similarly when they have to comprehend subject and object RCs. In particular, beyond the well-known subject advantage, we have provided evidence that OSV RCs are easier than OVS RCs for adults to process and for children to comprehend. We have also contributed to reinterpreting the previous report on French-speaking adults by
Schelstraete and Degand (
1998) that suggested that OVS structures were easier to process: a fine analysis of the data suggests that their conclusion was invalid. Although based on different type of measures (reading time and accuracy), our data converge toward the conclusion that children and adults are more likely to abandon a preferred analysis (subject RC analysis) when they encounter positive evidence as to what they have to do, i.e., the information that leads to abandon the preferred analysis also indicates how to revise it, rather than when they encounter a negative piece of information that only indicates that the preferred analysis is wrong. The difference between adults and children can be traced back to the ability to inhibit a preferred response. Children are known to have weak inhibitory skills. However, when they are able to abandon a preferred analysis, for them, as for adults, it is less difficult if they can rely on information that indicates what to do.