Y'all - Origin

Origin

Y’all clearly arose as a contraction of you-all. Y’all fills in the gap created by the absence of a separate second person plural pronoun in standard modern English. This absence arose when thou disappeared, and you came to signify both singular and plural. This absence similarly gave rise to the phrases you-uns, you lot, or you guys. (Cf. yous, an informal plural second-person pronoun formerly used in New York City, still common in Ireland, often rendered "youse" in Australia and New Zealand, and yinz, an informal plural second-person pronoun commonly used in Western Pennsylvania and the Appalachians); or vosotros, the Peninsular Spanish second-person plural, the latter having arisen when vos became the prevailing polite second-person singular term.)

Though the you all contraction argument may make sense when considering current-day vernacular, it is prudent to consider the vernacular which existed at the time which y’all was likely invented. By the late 18th century, Scots-Irish immigrants had settled in the Southern United States. It is well established that Scots-Irish immigrants frequently used the term ye aw. Some evidence suggests that y’all could have evolved from ye aw due to the influence of African slaves who may have adapted the Scots-Irish term..

There is evidence that the original spelling was ya'll. The spelling of ya’ll could have originated from the contraction of ya-all because ya was a common spoken slang form of the word you. 19th and 20th century authors like William Faulkner, Ernest Hemingway, and Carson McCullers used ya’ll. Though becoming less common, the spelling of ya’ll is still used within the Southern United States.