This book presents a richly illustrated, hands-on discussion of one of the fastest growing fields in linguistics today. The authors address key methodological issues in corpus linguistics, such as collocations, keywords and the categorization of concordance lines. They show how these topics can be explored step-by-step with BNCweb , a user-friendly web-based tool that supports sophisticated analyses of the 100-million-word British National Corpus. Indeed, the BNC and BNCweb have been described by Geoffrey Leech as "an unparalleled combination of facilities for finding out about the English language of the present day" (Foreword). The book contains tasks and exercises, and is suitable for undergraduates, postgraduates and experienced corpus users alike.