On the subject of impersonals
In accordance with basic principles of Cognitive Grammar, impersonal it (e.g. <i>It’s obvious that he’s angry</i>) is claimed to be meaningful. Three avenues of approach are followed in the characterization of <i>it</i> and the constructions it appears in: a comparison with related constructions; a comparison to other pronouns; and examination of a basic cognitive model called the “control cycle”. This broad perspective leads to a unified account in which the meaning of impersonal <i>it</i> is a special case of the general semantic value of this pronoun.