This document discusses the use of corpus and collocation in language classrooms. It defines a corpus as a large collection of texts stored electronically, and notes corpora can include newspapers, books, conversations etc. Collocations are frequently used word pairs or groups. The document provides examples of collocations and discusses how learning collocations can help students speak and write more naturally. It also describes different collocation activities that can be used in the classroom, including gap texts, sentences with errors, and categorizing expressions.