This paper explores the relationship between corpus linguistics and language teaching, with a particular focus on how corpora can inform both language pedagogy and classroom practice. It begins by defining the concept of a corpus and outlining the development of corpus linguistics as a methodological approach to language study. The paper then examines two major areas of pedagogical application: indirect and direct uses of corpora in language teaching. Indirect applications mainly involve syllabus design and teaching materials, where corpus-based evidence helps identify frequent vocabulary, typical collocations, and authentic patterns of language use, thereby narrowing the gap between classroom language and real-life language. Direct applications focus on classroom interaction, especially data-driven learning (DDL), which encourages learners to explore corpora themselves, observe language patterns, and induce grammatical and lexical rules. The study also discusses the role of specialized corpora, such as learner corpora and translation corpora, in areas including error analysis, English for Specific Purposes, and translator training. Through practical classroom examples, the paper illustrates how corpora can enhance the teaching of vocabulary, collocation, and grammar. Overall, the paper argues that corpus linguistics offers valuable methodological and pedagogical innovations for language teaching and holds significant potential for future development in materials design and instructional practice.