Acquisition of the T and C system in clausal complements

Abstract

In order to discover how children acquire the T(ense) and C(omplementizer) system, finite and nonfinite embedded clauses produced by children in the CHILDES database were studied. It was discovered that young children often delete to in nonfinite embedded clauses, and that they use that in the C position of finite imbedded clauses far less often than adults do. By adapting Wexler's (1998) theory of optional infinitives to a Pesetsky and Torrego (2001, 2002) framework, I show that the facts about both finite and nonfinite embedded clauses are due to three conflicting constraints: a modified Unique Checking Constraint based on that in Wexler (1998), a conceptual constraint requiring both T and C to appear in every full clause, and a constraint which tells children to use phonological closeness to decide which goal to move when two goals are equally close to a probe. Children cannot avoid violation of at least one constraint, so they are required to violate as few as possible. This results in different possible derivations, each one of which produces results which are seen in child speech.