Second year syntax: Questions and arguments
Many theories of syntactic acquisition, beginning with Chomsky 1965, model the relation between a corpus and an acquired grammar, abstracting away from development. In this talk, I examine how children deal with their input given only partial and changing knowledge of the target grammar. Focusing on the intersection between wh-movement, transitivity and verb learning, I show that by 15–16 months of age, children can use a verb’s distribution in transitive and intransitive clauses to draw inferences about its argument-taking properties. I also show that knowledge of transitivity precedes children’s ability to represent wh-dependencies, which are acquired by 18-months of age, but not before. But this raises two puzzles: (1) How can infants identify a verb’s transitivity given the high rate of wh-questions in speech to children; (2) What role, if any, does prior knowledge of argument structure play in the identification of non-local dependencies like wh-movement? I show computationally, (1) that it is possible for a learner to learn to “filter” non-basic clauses from their input in order to identify a verb’s transitivity properties, even without prior knowledge of what non-basic clauses look like, and (2) that unexpectedly missing arguments can provide a critical seed for the identification of the surface forms of non-local dependencies.