<P> Ain't meaning didn't is widely considered a feature unique to African American Vernacular English, although it can be found in some dialects of Caribbean English as well . It may function not as a true variant of didn't, but as a creole - like tense - neutral negator (sometimes termed generic ain't). Its origin may have been due to approximation when early African Americans acquired English as a second language; it is also possible that early African Americans inherited this variation from colonial European - Americans, and later kept the variation when it largely passed out of wider usage . Ain't is rarely attested for the present - tense constructions do not or does not . </P> <P> Linguistically, ain't is formed by the same rule that English speakers use to form aren't and other contractions of auxiliary verbs . Most linguists consider usage of ain't to be grammatical, as long as its users convey their intended meaning to their audience . In other words, a sentence such as "She ain't got no sense" is grammatical because it generally follows a native speaker's word order, and because a native speaker would recognize the meaning of that sentence . Linguists draw a distinction, however, between grammaticality and acceptability: what may be considered grammatical across all dialects may nevertheless be considered not acceptable in certain dialects or contexts . The usage of ain't is socially unacceptable in some situations . </P> <P> Functionally, ain't has operated in part to plug what is known as the "amn't gap"--the anomalous situation in standard English whereby there are standard contractions for other forms of to be not (aren't for are not, and isn't for is not), but no standard contraction for am not . Historically, ain't has filled the gap where one might expect amn't, even in contexts where other uses of ain't were disfavored . Standard dialects that regard ain't as non-standard often substitute aren't for am not in tag questions (e.g., "I'm doing okay, aren't I?"), while leaving the "amn't gap" open in declarative statements . </P> <P> Ain't has been called "the most stigmatized word in the language," as well as "the most powerful social marker" in English . It is a prominent example in English of a shibboleth--a word used to determine inclusion in, or exclusion from, a group . </P>

When did ain't get added to the dictionary