Noam Chomsky developed a theory of generational grammar.
Noam Chomsky . From 1951 to 1955 he was appointed to Harvard University 's Society of Fellows , where he developed the theory of transformational grammar for which he was awarded his doctorate in 1955 . He is credited as the creator or co-creator of the universal grammar theory , the generative grammar theory , the Chomsky hierarchy , and the minimalist program .