Used as a plural people is a form with no exactly corresponding singular. (English is not odd in this respect: the equivalent word is anomalous in Spanish, Italian, Russian, and many other languages.) In the past, grammarians have sometimes insisted that people is a collective noun that should not be used as a substitute for persons when referring to a specific number of individuals, as in Six people were arrested. But people has always been used in such contexts, and the distinction is now so widely ignored in general writing that it seems pedantic to insist on it. Persons is still preferred in quasilegal contexts, however, as in Vehicles containing fewer than three persons may not use the left lane during rush hours. Only the singular person is used in compounds involving a specific numeral: a six-person car; a two-person show. But people is used in other compounds: people mover; people power. These examples are exceptions to the general rule that plural nouns cannot be used in such compounds; note that we do not say teethpaste or books-burning.