Model learning in syntactic development: Intransitive verbs

Previous findings suggest that in natural language, frequency may be inherently correlated with generality, prototypicality or simplicity. The most frequently used instances in each domain may be the "best models" of that domain, so that the effect of input frequency is to have children learn the best exemplars of a domain first. To test this hypothesis, the first intransitive verbs to participate in multiword combinations were investigated, based on longitudinal observations of 20 children acquiring Hebrew. The results were compared to the frequency of intransitive verbs in multiword utterances in a speech corpus based on recordings of 48 mothers. The first verbs that begin the acquisition of intransitive word-combinations are the most frequent intransitive verbs in the input. These verbs also tend to be relatively nonspecific, general, or generic intransitive verbs with light semantics. The same verbs that children first combine with subjects or locative adjuncts, and which are the most frequent in the speech of mothers, are typical grammaticalized markers of intransitivity or directional-movement in many languages. These results join many previous findings in showing that the statistical structure of natural languages makes possible, at the onset of acquisition, a kind of lexical learning which is at the same time a type of category-or rule-formation.