This is an introductory course in Second Language Acquisition (SLA). How adults learn, or fail to learn, a second language is a fascinating question. It involves much of what we know about human cognition, psychology, and language. How best to help learners acquire a second language is an equally important educational issue. In addition to all of the factors which play a role in child language acquisition, SLA also involves effects of variation in second language educational, social and usage environments, ages of acquisition, levels of learner cognitive and brain development, motivation, and language transfer.