Noam Chomsky is known for his

The correct option is Generative grammar.

Noam Chomsky is a pioneering American linguist, cognitive scientist, and philosopher who revolutionized the study of language in the mid-20th century. He is widely recognized for developing the theory of generative grammar, which posits that human beings possess an innate, biological capacity for language acquisition.

Chomsky argued that the human brain has an underlying framework, often called Universal Grammar, which allows individuals to generate an infinite number of novel, grammatically correct sentences using a finite set of structural rules. This shifted the study of linguistics from observing external speech habits (structuralism/behaviorism) to investigating the cognitive processes behind language creation and understanding.