This unit provides an overview of approaches to the study of second language acquisition (SLA). It deals with key linguistic, psycholinguistic and sociocultural theories of how language is acquired or learned. Topics covered include: the nature of learner language, competence versus performance, interlanguage, the role of input and interaction, transfer, linguistic universals, bilingual acquisition, individual learner differences such as age, learning style, motivation and personality, and second language acquisition in instructed environments. Web access is essential.