 Ain 't was a prominent target of early prescriptivist writers. In the 18th and early 19th centuries, some writers began to propound the need to establish a "pure" or "correct" form of English. Contractions in general were disapproved of, but ain't and its variants were seen as particularly "vulgar." This push for "correctness" was driven mainly by the middle class, which led to an incongruous situation in which non-standard constructions continued to be used by both lower and upper classes, but not by the middle class. The reason for the strength of the prescription against ain 't is not entirely clear.
