<P> 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 . </P> <P> The strong prescription against ain't in standard English has led to many misconceptions, often expressed jocularly (or ironically), as "ain't ain't a word" or "ain't ain't in the dictionary ." Ain't is listed in most dictionaries, including the Oxford Dictionary of English and Merriam - Webster . However, Oxford states "it does not form part of standard English and should never be used in formal or written contexts", and Merriam - Webster states it is "widely disapproved as non-standard and more common in the habitual speech of the less educated". </P> <P> Webster's Third New International Dictionary, published in 1961, went against then - standard practice when it included the following usage note in its entry on ain't: "though disapproved by many and more common in less educated speech, used orally in most parts of the U.S. by many cultivated speakers esp. in the phrase ain't I ." Many commentators disapproved of the dictionary's relatively permissive attitude toward the word, which was inspired, in part, by the belief of its editor, Philip Gove, that "distinctions of usage were elitist and artificial". </P> <P> Ain't is found throughout the English - speaking world across regions and classes, and is among the most pervasive nonstandard terms in English . It is one of two negation features (the other being the double negative) that are known to appear in all nonstandard English dialects . Ain't is used throughout the United Kingdom, with its geographical distribution increasing over time . It is also found throughout the United States, including in Appalachia, the South, New England, the Mid-Atlantic, and the Upper Midwest . In its geographical ubiquity, ain't is to be contrasted with other folk usages such as y'all, which is confined to the South region of the United States . </P>

When did they add ain't to the dictionary