I really recommend this book as an introduction to Second Language Acquisition (SLA) reasearch. It was written with the language teacher in mind. Many of the other books on the subject are focused on the researcher rather than the teacher, so this book fills a gap in the literature. The explanations of the major theories are carried out without frequent use of jargon, so it's easy for the beginner to get a handle on SLA theory. I even recommend this for students who are studying SLA in graduate school. This will provide an excellent introduction that could be read before reading more difficult texts. After readinging "How Languages Are Learned", you'll understand more in depth discussions about the theories covered. A must for all practicing language teachers.