Language has been thought to be the object of linguistics. But Noam Chomsky insists that language is a useless notion for linguistic science. He argues that linguistics should be concerned with grammar. He renames language and grammar,　externalized language (E-language) and internalized language (I-language) respectively. According to Chomsky, E-language (language) is something abstract externalized from the actual apparatus of our mind and I-language (grammar) is the physical mechanism of our brain. If we are endowed with Universal Grammar (UG) at birth and get I-language after parameters built in UG are set one way or another and I-language generates E-language, then I-language will be the object of linguistic science. But if there is nothing but language (E-language) spoken or written around us and grammar (I-language) is regularity derived from language (E-language), then we will have a quite different story. In other words, language spoken or written around us will be the object of linguistic science.