This book examines the processes involved in acquiring language skills, both mental and social, and the notion of what makes a skilled language learner. At the same time the author discusses what is known about teaching procedures and how they are used by the learner; how tasks are set up, how tasks determine the student's approach, how teachers" feedback is formulated and how students use the feedback and incorporate it in the development of their skills in the language. Throughout the discussion the author presents the growing body of knowledge from qualitative and descriptive research on second language development and draws implications for the development of teaching and learning strategies.