The author discusses claims that linguistics can solve the problems of language teaching. Linguistics is either a theory of language or a description of a particular language, and both vary greatly from investigator to investigator, both as to scope and substance. Linguistic "analysis is the business of the linguist" but it is not essential to the learning of a language, and the units of analysis may not be the same as those needed for learning the language. The linguist's prediction of expected errors, based on contrastive analysis of native and target languages, is not as useful for teaching as the experience of teachers listing actual errors made. Most contrastive descriptions are so "incomplete as to be misleading." Linguistics can help the teacher to know more about the foreign language, which, in turn, can help his teaching of it. The author concludes: "Contemporary claims that applied linguistics can solve all the problems of language teaching are as unfounded as the claims that applied psychology can solve them. For the problems of language teaching are central neither to psychology nor linguistics." (MK)