"You may not agree with Chomsky`s work, but it would be both short-sighted and unscholarly to ignore it." (Smith 2000:vi) Sung-Hyuk Park. 2002. Chomsky`s Conception of Language and Grammar. Studies in Modern Grammar 31, 25-46. Chomsky`s views on human language and the nature of linguistic inquiry are very widely referred to, but equally widely misrepresented. Such widespread misunderstanding of Chomsky`s linguistic ideas seem, especially in Korea, to be due in part to misinterpretation of his conception of language and grammar. The purpose of this paper is to reexamine Chomsky`s conception of language and grammar with a view to helping Korean critics of Chomskyan theory understand it in a reasonable manner. According to Chomsky, "there is a faculty of language FL, a component of the human mind/brain dedicated to language," and "FL undergoes state changes under triggering and shaping influences of the environment." The most important and basic assumption of Chomskyan theory is the internalist conception of knowledge of a language, according to which such knowledge is constituted solely as part of the psychology of individuals. This special notion is accordingly referred to as "I-language," where I is to suggest "individual," "internal," and "intensional." The notion of language that is being investigated is the language of an individual (I-language), not the language of a community or a country or an era. An I-language L is thus defined as the language of an individual whose FL is in a state L (S?). The notion of grammar should then be conceived of in the same vein: the term "grammar" is the linguist`s theory of the I-language, universal grammar (UG) being the theory of the initial state S? of FL, which is uniform for the species.