Abstract
Research on first language acquisition in young children and second language learning in older children and adults has examined the possible role played by maturational constraints (related to the notion of a critical period for language acquisition). The following article reviews findings from investigations that studied the special circumstances of delayed first language learning and the effect of age on second language learning. Findings suggest that: (a) the observed phenomenon of a critical period in language development merits further study, and (b) the ability to attain native-speaker grammatical competence may actually begin to diminish earlier than puberty. The discussion of the current research presents bilingual educators with a new framework from which to reconsider a number of pedagogical issues and recent controversies regarding school language policy.