Chomsky, Noam, CHOM skee, nohm (1928-...), is an American linguist, philosopher, and political activist. He revolutionized the study of language with his introduction of generative grammar, also called transformational grammar. Generative grammar is a set of largely unconscious rules that speakers use to produce and understand sentences in their language. Chomsky argued that certain universal properties underlie all languages, and that these properties are innate (inborn). His research has influenced theories of innate ideas in philosophy, psychology, mathematics, and education.