M.A.K. Halliday was a prominent linguist from Australia, known for his contributions to the field of systemic functional linguistics. Born in 1925, he developed theories that emphasize the relationship between language and its social context, focusing on how language functions in communication. Halliday's work has influenced various disciplines, including education, sociolinguistics, and discourse analysis. He introduced concepts such as the three metafunctions of language: ideational, interpersonal, and textual, which help explain how language conveys meaning and serves different purposes in society.