This coursebook demonstrates the relevance of linguistic expertise for the EFL classroom. It explores a wide range of topics (phonetics/phonology, lexis, corpus linguistics, text linguistics and the power of language) always keeping one central question in mind: Why should a future teacher of English know about this? With its highly accessible style and layout, a wealth of examples and exercises as well as a large range of additional innovative online materials this textbook sets out to convince its readers that they will be better teachers if they are good linguists.