The Routledge Handbook of Instructed Second Language Acquisition is the first collection of state-of-the-art papers pertaining to Instructed Second Language Acquisition (ISLA). Written by 45 world-renowned experts, the entries are full-length articles detailing pertinent issues with up-to-date references. Each chapter serves three purposes: (1) provide a review of current literature and discussions of cutting edge issues; (2) share the authors’ understanding of, and approaches to, the issues; and (3) provide direct links between research and practice. In short, based on the chapters in this handbook, ISLA has attained a level of theoretical and methodological maturity that provides a solid foundation for future empirical and pedagogical discovery. This handbook is the ideal resource for researchers, graduate students, upper-level undergraduate students, teachers, and teacher-educators who are interested in second language learning and teaching. .