Requiring no prior knowledge of the subject, this text tackles basic questions central to the study of psycholinguistics, such as whether language is restricted to humans, whether there is biological evidence for innate language activity, how children learn language, and how we understand, plan and produce language. The author investigates these issues with regard to animal communication, child language and the language of adults, and provides references and suggestions for further reading.;The book has been substantially revised, in particular taking account of the considerable changes in Chomsky's recent ideas. As a result, the chapters on grammatical innateness, child language acquisition and speech comprehension have been largely rewritten.