A language teaching syllabus involves the integration of subject matter (what to talk about) and linguistic matter (how to talk about it); that is, the actual matter that makes up teaching. Choices of syllabi can range from the more or less purely linguistic, where the content of instruction is the grammatical and lexical forms of the language, to the purely semantic or informational, where the content of instruction is some skill or information and only incidentally the form of the language. To design a syllabus is to decide what gets taught and in what order. For this reason, the theory of language explicitly or implicitly underlying the language teaching method will play a major role in determining what syllabus is adopted. Theory of learning also plays an important part in determining the kind of syllabus used. For example, a syllabus based on the theory of learning espoused by cognitive code teaching would emphasize language forms and whatever explicit descriptive knowledge about those forms was presently available. A syllabus based on an acquisition theory of learning, however, would emphasize unanalyzed, though possibly carefully selected experiences of the new language in an appropriate variety of discourse types.
The choice of a syllabus is a major decision in language teaching, and it should be made as consciously and with as much information as possible. There has been much confusion over the years as to what different types of content are possible in language teaching syllabi and as to whether the differences are in syllabus or method. Several distinct types of language teaching syllabi exist, and these different types may be implemented in various teaching situations.