This core textbook exposes students to the key theories, ideas and assumptions which underpin language study. Enlivened by a wealth of debates from across the field, it provides an accessible and engaging introduction to the history of linguistic theory and the variety of theoretical approaches to language study. Balancing theory with application, the first few chapters present an overview of the key issues in language theory, while later chapters focus on the application of language theory and serve as a starting point for readers to investigate various approaches for themselves. Written in response to the needs of teachers of English language undergraduates, this is an ideal volume for all students studying English language, whether as a single subject or as part of a more general degree programme.