This book deals with words, and how humans learn them, remember them, understand them and find the ones they want. It discusses the structure and content of the human word-store or 'mental lexicon' with particular reference to the spoken language of those with English as their native language. Since the first two editions of Words in the Mind were published, work on the lexicon has expanded quickly. This growth is reflected in this third edition, which contains substantial new material. There is an extra chapter on layering and meaning change, and several others have been considerably enlarged. The notes and suggestions for further reading have been updated, and many new references have been included. The book remains accessible in style and easy to read for both undergraduates and non-specialists.