Abstract
Based on a 70,000-word sample of eight journal articles and four textbook chapters, this article examines the communicative value of anticipatory- it clauses in scientific and technical texts. The main discourse function of the 205 clauses appears to be to provide author comment, with the meaning of the verb or the meaning of the adjective determining the particular type of comment. Many of these comments are evidential; that is, they are concerned primarily with the reliability or source of knowledge. Anticipatory- it clauses are also used to mark the introduction of a topic, to forecast, to summarize, and to direct the reader in interpreting a graphic or recognizing the most salient points in an argument. Rather than being a structure to avoid, the anticipatory- it clause is probably one whose effective use indicates academic acculturation.