"A comprehensive and coherent account of the research and theory in the field of second language acquisition, including chapters on instructed SLA. This book is an encyclopedic survey of second language acquisition research as this has developed over the last forty years. It provides sections on the description of learners' language, the role of the linguistic environment and social context, internal mechanisms, individual learner differences, and the role of instruction. It provides a balanced account by representing a variety of perspectives, including cognitive, linguistic, sociocultural, and neurolinguistic. "--Publisher's website.