Now in a fifth edition, this bestselling introductory textbook remains the cornerstone volume for the study of second language acquisition (SLA). Its chapters have been fully updated, and reorganized where appropriate, to provide a comprehensive yet accessible overview of the field and its related disciplines.

This has always been a go-to introductory textbook and it is a bestseller because it contains everything readers need to know about the field. Now in a fifth edition, it is once again absolutely state-of-the-art in its comprehensive coverage, easily readable style, and now includes helpful new pedagogical tools. It is an ideal text for introductory classes in applied linguistics and second language research, and a critical resource for more advanced courses or researchers in those areas as well as in general linguistics, TESOL, and language education. Every SLA researcher, novice or experienced, will benefit from having this book on their bookcase.

Alison Mackey, Georgetown University & Lancaster University

Second Language Acquisition: An Introductory Course, with Sue Gass, Jennifer Behney, and Luke Plonsky at the helm, has always been outstanding, but manages to improve with every new edition. The authors are established experts; the coverage is up to date, balanced, and comprehensive; and the presentation is lucid – even when dealing with what is sometimes quite complex material. The book is intended as an introductory text but is intellectually stimulating, and in my experience consistently "hooks" undergraduate and graduate students alike, motivating many of them to pursue doctoral work in SLA, second language studies, linguistics, applied linguistics, second language education, or TESOL. Highly recommended.

Michael H. Long, University of Maryland-College Park

Building on both foundational and cutting-edge research in the field of Second Language Acquisition and drawing from a range of disciplinary perspectives, this user-friendly text is highly engaging, resource-rich, and clearly organized. This new edition provides an excellent introduction to the study, practice, and science of how humans learn second (and additional) languages.

Kendall A. King, University of Minnesota-Twin Cities

The authors have expertly updated, expanded and reorganized this new edition of what is arguably the foundational textbook for the study of second-language acquisition research. I have made the previous editions required reading in my SLA courses over the past twenty-five years, and I have never been disappointed with the students’ reaction to the organization and presentation of the content. This text provides students with an excellent basis for gaining applicable background knowledge in the area, or for deeper investigation into the subject matter.

Fred Eckman, University of Wisconsin-Milwaukee

The arrival of the new version of this well-loved text could be compared with the launch of a new version of a well-known eco-friendly luxury car: It has the quality and the familiarity of the old model combined with the latest breakthroughs. This fifth edition provides students and researchers with the knowledge and tools to move the field forward.

Jean-Marc Dewaele, Birkbeck, University of London

This book is a truly valuable resource for both students and scholars wishing to expand their knowledge of the field of second language acquisition and gain a solid understanding of its core pursuits, findings, theories, principles, and methods. The book is current, comprehensive, and clearly written, and offers just the right amount of explanation and illustrative examples. Importantly, it also prompts readers to think through the presented arguments and evidence in order to draw their own conclusions and generate their own insights.

Scott Jarvis, University of Utah

In keeping with the tradition of excellence established with the first edition of this text, the fifth edition provides a comprehensive introduction to the state of the art in research in SLA. While it retains the features that have made it the staple text for generalist SLA courses, its organization has been further strengthened to help students fit together the many puzzle pieces that make up this critical area of applied linguistics.

Lucy Pickering, Texas A&M University-Commerce

Susan M. Gass is University Distinguished Professor of Second Language Studies at Michigan State University. She has served as president of the American Association of Applied Linguistics (AAAL) and the International Association of Applied Linguistics (AILA). Throughout her career, she has made groundbreaking contributions to advance the study of SLA, and remains one of the leading figures in the field. She is the winner of numerous local, national, and international awards.

Jennifer Behney is Associate Professor of Italian and Applied Linguistics in the Department of World Languages and Cultures at Youngstown State University. Her work has appeared in Foreign Language Annals, Studies in Second Language Acquisition, and several book chapters, and she was co-editor of a volume on salience in SLA. She was the recipient of the 2019 Ed Allen Award for Outstanding College World Language Instructor.

Luke Plonsky (PhD, Michigan State University) is Associate Professor of Applied Linguistics at Northern Arizona University, where he teaches courses in SLA and research methods. His work in these areas can be found in over seventy articles, book chapters, and books. Luke is Senior Associate Editor of Studies in Second Language Acquisition, Managing Editor of Foreign Language Annals, Co-Editor of de Gruyter Mouton's Series on Language Acquisition, and Co-Director of the IRIS Database (iris-database.org). In addition to prior appointments at Georgetown University and University College London, Luke has taught in Japan, the Netherlands, Poland, Puerto Rico, and Spain.