This book is a comprehensive treatment of the literature on second language acquisition in childhood, viewed in terms of contemporary process models. After a general introduction on bilingualism in society, six major topics are considered: first-language acquistion, language acquisition and learning in childhood and adulthood, simultaneous acquisition of two languages in childhood, successive acquisition of two languages in childhood, second-language programs in elementary school and some effects of bilingusalism. Basic to the whole discussion is the examination of first language acquisition: the skills the child is thought to bring to the process, tasks to be accomplished, and developmental stages. The other topics considered are: the critical period hypothesis, developmental processes involved in simultaneous and successive acquisition of a second language, the effect of interference, code-switching, second language programs for children in the United States and Canada, the effects of bilingualism, and research dealing with cognitive processes in bilingual individuals. Three tentative conclusions are drawn. These deal with cognitive strategies, description acquisition, storage and retrieval of first and second languages. (AMH)