AMONG THE SYNTACTIC UNITS with which analyses of contemporary English are concerned, none are of greater importance than clauses, main and subordinate. It is surprising that in the present period of strong interest in structural analysis of the living language no simple and convincing descriptions of clause patterns in present use are available. The purpose of this paper is to summarize briefly what seem to be the most influential recent descriptions of clause patterns and then to attempt a more satisfactory description. We can turn to Roberts's Understanding Grammar1 for a good presentation of the usual school-grammar classifications. Roberts has declarative, imperative, interrogative, and exclamatory main clauses, the exclamatory ones being marked by what and how. He rejects the notion of infinitival, gerundial, and participial clauses-largely, he says, because acceptance of it would make it hard to name the subordinate-clause types. His subordinate clauses are classified as adjectival, adverbial, and nounal, on the basis of function primarily. For example, because I am driven away is classified as a noun clause in if I leave, it will be because I am driven away. His markers for 'adverbial' clauses include sequences such as provided that, in that, now that, so that, such that, in order that, and as soon as. His subclassifications of adverbial clauses are made on the basis of meaning. The New Linguists have done no better with clause patterns. Fries's Structure of English2 recognizes questions, requests, and statements as clause patterns commonly given sentence status. Fries classifies clauses such as rarely do we eat before seven as statements with exceptional word order, and gives a similar classification to clauses such as were they all here in were they all here we should have a quorum. Emotional was he mad! is also a statement. In will you take down this message for him the first two words are simply a 'polite formula' preceding a request. One group of Fries's function words is made up of 'functioning units by means of which sentence units are included in larger structures.'3 He includes in the group not only such markers of subordinate clauses in which they are contained as when, although, which, and that, and