This book introduces research-based SLA acquisition theories and provides practical suggestions for applying them to language learning courses in relation to their syllabus, materials, methodology, and assessment. It is written to be engaging and relevant for students, researchers and practitioners. 'Establishing a lucid connection between theory and practical application is no small task. In this book, Tomlinson and Masuhara succeed in bridging this important gap, illustrating the relevance of SLA theory in the classroom setting. This book is an especially helpful guide to educators seeking to engage more with SLA theory. A valuable contribution to the field.' Michael T. Putnam