A review of a range of usage handbooks reveals that many manuals advise against the use of words, phrases, and sentence types on the basis of commonly held beliefs rather than of empirical studies of the characteristics of the items and the ways in which professional writers actually use them. One element castigated by the manuals is expletive it, particularly when followed by a form of the verb be. This study distinguishes three constructions which begin with it is (extrapositive, cleft, and inferential), examines their linguistic characteristics, notes differences in meaning and function between them and their expletiveless counterparts, and explores the uses made of them by writers of fiction and nonfiction. The study demonstrates that although conventionally meaningless, expletive it is introduces sentence types with pragmatic and textual properties of considerable value to writers. The constructions are associated with specific interpretations beyond their conventional meanings. These interpretations provide writers with resources for creating subtle and significant local textual effects.