The usage of a language is the manner in which the written and spoken language is routinely employed by its speakers; that is, it refers to "the collective habits of a language's native speakers", as opposed to theoretical or idealized models of how a language works or (should work) in the abstract. Fowler characterized usage as "the way in which a word or phrase is normally and correctly used" and as the "points of grammar, syntax, style, and the choice of words."
In the descriptive tradition of language analysis, "correct" tends to mean "functionally adequate for the purposes of the speaker or writer using it"; usage is also, however, a concern for the prescriptive tradition, for which "correctness" is a matter of arbitrating style.
Dictionaries are not generally designed to participate in linguistic prescriptivism (with the notable exception of the American Heritage Dictionary), and are thus not intended to guide "good usage" in the latter sense. "Despite occasional usage notes, lexicographers generally disclaim any intent to guide writers and editors on the thorny points of English usage."
According to Jeremy Butterfield, "The first person we know of who made usage refer to language was Daniel Defoe, at the end of the seventeenth century". Defoe proposed the creation of a language society of 36 individuals who would set prescriptive language rules for the approximately six million English speakers.