One of the fundamental questions in the field of language acquisition is a learnability problem, which considers how learners acquire certain aspects of language which are not directly provided in the input or whose referents are not readily observable. This dissertation investigates Japanese children's acquisition of various linguistic phenomena,…

Explores the underlying knowledge that children have about the relationship between the structure of requests and the relative status of speakers and listeners. Shows that the three age groups (preschoolers, 5-year-olds, and 10-year-olds) could systematically differentiate the requests by means of syntactic directness or semantics. (HOD)