When infinitives are not under control: the Growing Trees Hypothesis and the developmental advantage of restructuring verbs

This study contributes novel insights into the acquisition of infinitival structures by exploring the syntax of restructuring verbs in relation to language development. Despite selecting infinitival complements, restructuring verbs exhibit a syntactic behavior typical of simple clauses (Rizzi 1976). This unique property gave rise to two main syntactic perspectives: monoclausal and biclausal approaches (Wurmbrand 2001). The former usually assume that the restructuring verb and its infinitive never constitute two separate domains, whereas the latter derive monoclausality throughout the derivation. In this study, we analyze the predictions arising from the intersection of a specific monoclausal approach to restructuring, that reinterprets restructuring verbs as being functional elements in the inflectional field (Cinque 2006), and the Growing Trees Hypothesis (GTH), which assumes that syntactic development proceeds bottom-up in subsequent cartographically defined stages (Friedmann, Belletti & Rizzi 2021). We show that restructuring verbs not only emerge earlier than control structures, but they do so in compliance of the predictions of the GTH if they were inflectional elements (Cinque 2006). Our data is then evidence against theories of restructuring that rely on the presence of an embedded CP domain.