Basic to composition skill is control of sentence structure and accuracy in mechanics. Although it is often said that a student should not write what he has not first heard and practiced orally, it might equally well be said that he should not be expected to write grammatical patterns that he has not read, inasmuch as there is a difference in the structures used in speech and writing. One approach to developing control over patterns in writing is through transformational grammar, because it provides (1) a systematic method of constructing sentences; (2) a device for identifying faulty constructions; and (3) an understanding of how structures which seem similar on the surface may be quite different structures with quite different meanings ("Grading papers/crying babies can be a nuisance"). Studies conducted in the combining of simple statements into more complex sentences show that the more mature and skillful the writer, the more he uses transforms, particularly nominal-producing transforms. The author suggests having students first express their ideas in short simple sentences to develop a feeling for the essential elements of a sentence. They may then move on to combining by coordination or subordination with an adverb clause, passive forms, relative and noun clauses, and verbals. An exercise in combining sentence patterns concludes the paper. (AMM)