This document discusses the importance of genres in English language teaching materials. It notes that exposing learners to different genres through course books helps them build linguistic knowledge and communicate effectively. Course books contain various written and visual genres like letters, advertisements, articles and internet pages. The inclusion of diverse genres and multimodal elements makes learning feel more relevant to real-world language use. Good textbooks should offer a variety of genres to familiarize students with genre conventions and cultural contexts. While textbooks are useful learning tools, teachers must help students transfer genre knowledge from classroom to social situations. Overall, the document emphasizes how understanding genres can improve second language acquisition and communication.