Dr Isabelle Roy | On the development of Merge and recursion in the transition from single words to sentences: Tracking the development of syntactic complexity in early child language

The Minimalist Program (Chomsky, 1995), reducing the fundamental complexity of grammatical processes to Merge and recursion, has potential for providing a developmentally flexible model for the path from initial two-word productions to full adult grammatical structure (Powers 2002, Ninio, 2006, 2011; Roeper 2007, 2011). We investigate the earliest predicative combinations produced by three English-learning children, tracing the development of their grammatical systems over the first four months. The study of verbs and their arguments indicates that the application of merge develops (including the nested application of Merge, i.e., recursion) such that initial limited application is followed by broader application to a full range of linguistic environments. Even though children use Merge correctly very early, they do not always use it in all and exactly the contexts adults do. Unlike adults, we argue, children also make use of simple juxtaposition: a conceptual rather than a grammatical operation which puts two elements together in an unordered, unstructured sequence. The possibility to use juxtaposition in early child language relates to (possible absence of) labeling. Recourse to juxtaposition is expected to decline as facility using Merge increases to eventually reach the target grammar. We take early developmental work (Werner & Kaplan, 1963) as inspiration for understanding this development (McCune, 2008). We demonstrate that direct measurement of the grammatical complexity of children’s combinations provides information beyond MLU alone. A generative developmental approach is effective for the analysis of early child language, allowing for assessment of growth in a manner continuous with analyses of the adult system, and capable of elucidating individual differences in development as well as language differences.

(joined work with B. Copley and L. McCune)