Abstract

Universal Grammar (UG) is a theory about the innate linguistic knowledge that child language learners bring to the task of language acquisition. This chapter examines the findings of experimental research on children's knowledge of one principle of UG, called Principle C. It presents the defining properties of Principle C. The chapter reviews empirical evidence showing that children apply Principle C to a range of disparate‐looking phenomena. It also presents empirical findings that document children's assignment of hierarchical structure to strings of words. The empirical evidence supports a conclusion – that child language learners access a level of linguistic representation in addition to the constituent structure that is formed using Merge. This additional component of the language apparatus is called Logical Form. The chapter looks at a string of words where Principle C applies at the level of Logical Form. Cleft sentences are one such case.