universal grammar
【正确答案】：Universal grammar, also known as the principles-and-parameters theory, is a system of linguistic knowledge and a human species-specific gift which exists in the mind or brain of a normal human being. Its general principles include case condition and adjacency condition, the former requires that a noun phrase must have case and case is assigned by verb or preposition to the object position, or by auxiliary to the subject position; the latter states that a case assignor and a case recipient should stay adjacent to each other, which explains why no other phrasal category can intervene between a verb and its direct object. The parameters on the other hand includes adjacency parameter anddirectionality parameter. The former accounts for the specific word order patterns of a certain language, the latter concerns the directionality of case assignment.
