This document discusses the functions of language. It begins by introducing language and providing definitions of language from Henry Sweet and Noam Chomsky. It then discusses M.A.K. Halliday's classification of the macro-functions and micro-functions of language. The four basic or common functions of language are described as the informative/communicative function, emotive/expressive function, phatic or social function, and directive function. Examples are provided for each of the four basic functions.