M. A. K. Halliday was a prominent linguist known for his work in the field of systemic functional linguistics. Born in 1907 in England, he made significant contributions to understanding how language functions in social contexts. His theories emphasize the relationship between language and its use in communication, focusing on how people convey meaning through language. Halliday's influential ideas include the concept of register, which refers to the variations in language use depending on context, and the notion of metafunctions, which describes the different purposes language serves. His work has had a lasting impact on linguistics, education, and language studies worldwide.