Sociolinguistics and Transformational Grammar* Masayoshi Shibatani 1. The success of transformational · grammar owes a great deal to its high degree of idealization. By assuming an unrealistic ideal speaker/ hearer in a homogeneous linguistic community, and by proposing the explication of this speaker's linguistic ability to be its ultimate goal, transformational grammar devised a system of grammar which has even become one of the standard notions of the discipline today. Sociolinguistics, on the other band , is a discipline that has developed itself with a methodology which diametrically oppose s that of transformational grammar. Its ·remarkable progress in recent years has led Dell Hymes, William Labov, and M.A .K. Halliday to assert that sociolinguistics is linguistics, and hen ce the prefix "socio·" is redundant and unnecessary (Halliday, 1974: 81). The recent rise of sociolinguistics is not unrelated to inherent problems in the transforma- tional approach. In fact, Labovian sociolinguistics has developed by challenging the methodology utilized in transformational grammar. In this paper I want to attempt an .analysis of reasons behind this rise of sociolinguistics, focusing particularly on those .aspects of transformational grammar which ate questioned by sociolinguists and others . 2. The fundamental difference between transformationally-based linguistics and sociolin- guistics is found in the extent of idealization . with respect to their data. As mentioned in the beginning, transformational grammar determines its subject of investigation to be the ideal speaker/ hearer (hereinafter referred to as the 'speaker' ) in an idealized, or completely homogeneous linguistic community. In other words, such a speaker is never subject to dialectal variations, memory limitation, and attention and is one who never makes any mistake in his linguistic production. The problem that emerges in attempting to explicate the linguistic competence of .such an idealized speaker lies in the specification of the data base for investigation. Noam Chomsky saw the possibility of the actual linguistic production being greatly altered by a variety of factors involved in linguistic performance. He, therefore, determined his - data for analyses to be the linguistic intuition and introspective judgements by the native oSpeaker of a particular language. In his own words, "Intuitive and introspective judgements . are the primary data for the descriptive grammarian, hence also the linguistic theorist ( Parret , 1974: 40 , Chomsky) ." Such a format of investigation based on the idealization of the linguistic community * An earlier version of this paper appeared in Japanese in Gengo vol. 11. 10. 103