This paper is a short tutorial in formal grammar with speculative examples of how it could be used as a research tool for task analysis, the description of lesson structure, the modeling of interactive dialogue, and perhaps the instructional design process. Gagne's notion of "events of instruction" is used in an example of the application of linguistic techniques to instructional system design, and it is suggested that use of analogy is one way to think about the problems involved, e.g., the events of instruction may be compared to parts of speech, and sentences are made up of parts just as lessons are. It is argued that sentences are infinite in variety but constrained structurally; some instructional designs may be thought of as well-formed strings while others may violate our intuitions of well-formedness; and a grammar of instructional design would assign descriptions to lesson materials. A brief explanation of the term "formal grammar" as used in linguistics is followed by descriptions of other grammars proposed by researchers, including a story grammar, a cinema grammar, a computer-interface grammar, a lesson grammar, and a grammar of instructional design. A summary suggests that while the ideas presented in this paper are far from complete, formal grammar as an instructional design device will at least facilitate the identification of testable hypotheses about optimal sequences, and might also be modified to help designers generate lessons more fluently or to allow the computer generation of large numbers of different, acceptable lesson structures that can be fleshed out by subject experts. The various grammars described are presented in nine figures. (11 references) (BBM)