Can y'all be used to refer to a single person?
The singular y'all is the Loch Ness Monster of dialect study
"Y'all" is the most identifiable feature of the dialect known as Southern American English. It simply and elegantly fills out the pronoun paradigm gap that occurs in dialects that have only "you" for both singular and plural. Even people who don't speak the dialect, who sometimes look down on its other features, have a soft spot for "y'all." It's as American as can be, and it embodies our ideal national self-image: down-to-earth, charming, and useful. But there is also a mysterious side to "y'all," and for over a century, a controversy has been brewing over what might be called the Loch Ness Monster of dialect study: the elusive singular "y'all." There are a few who claim to have seen it in the wild, and many who denounce such claims as nonsense. Does it exist?
Most Southerners say no. The whole idea of singular "y'all" strikes them as, at best, the fanciful invention of confused and clueless Northerners, and, at worst, an outrageous insult. In the early 1900s, C. Alphonso Smith, a North Carolina-born literature professor, used to read aloud passages to his students from "Southern" novels written by Northerners that contained phrases like "Maw, y'all got a hairpin?" and "in every case the misapplied idiom was greeted with mingled incredulity and laughter." Tearing down the myth of singular "y'all" became a matter of regional pride. As Linguist E. Bagby Atwood put it in his 1962 study of Texas English, "if anything is likely to lead to another Civil War, it is the Northerner's accusation that Southerners use you all to refer to only one person."
No one disputes that "y'all" is sometimes addressed to a single person. You can walk into a store and say to the clerk, "Y'all got any eggs?" But every Southerner knows that this is not really a form of singular address. The "y'all" in that case means "you and your associates." In "How y'all doing?" it means "you and your family." In "Where do y'all buy groceries around here?" it means "where do you and the other people in this neighborhood buy groceries?" The plurality is implied, and if you can't see that, well, you got less sense than a hound dog chasing a porcupine in a rain barrel.
Still, there are documented cases of actual Southerners using "y'all" as a form of singular address that aren't easy to explain away with the implied plural principle (many of them discussed in the pages of the journal American Speech): A waitress, saying to a customer eating alone, "How are y'all's grits?" A shopgirl, saying to a lone customer, "Did y'all find some things to try on?" A student, saying to her professor "Why don't y'all go home and get over that cold?" Could these be mishearings or misunderstandings? Possibly. But another explanation is that every once in a while, "y'all" is used as a mark of formality. When "you" feels a little too direct, the plural adds a little distance and deference. It wouldn't be the first time this happened in language evolution. The formal "you" is the same as the plural "you" in French, German, and plenty of other languages.
"Y'all" might also take on the role of a formal marker through a sweetening effect. If you wrap the message in an extra layer of Southernness, it goes down easier. In a 1984 paper on the "y'all" controversy, Gina Richardson gives a few examples of the ways Southerners do just this. They exaggerate their dialect in front of outsiders for social purposes:
One woman reported that she had purposely used exaggerated speech on a recent trip when she had unwittingly aroused the anger of a New York bus driver, and decided it would be a good idea to stress her lack of New York savvy. A college student mentioned that she tended to use exaggerated Southern when she was trying to soften advice that might not be well received — for example, when she indicated her disapproval of her roommate's fad diet.
Maybe Northerners aren't just making stuff up. They have been hearing singular "y'all" all along. They just didn't realize it was not part of Southern English, but a different dialect, Exaggerated Southern English. The very fact of their not being Southern is what brings the singular "y'all" into existence.
Of course, if an exaggerated dialect becomes enough of a habit, it can spread to in-group contexts too. This may have happened in some large cities in the South. In a 1998 survey study by Jan Tillery and Guy Bailey, one-third of Oklahomans said they used singular "y'all." (This wasn't just an Oklahoma quirk; a 1994 Southern Focus Poll found the same thing.) When Tillery and Bailey (for the record, Southerners themselves) broke down the results by social characteristics, there was one significant difference. There were more singular "y'all" users in urban metro areas (Oklahoma City and Tulsa) than non-urban ones. This wasn't due to outsider transplants to those cities; natives actually admitted to it more. Overall, the form was "more likely to be used by better educated Oklahomans than by less educated ones, by urban residents than by rural ones, by middle-aged adults than by older or younger ones, and by men than by women."
There is something counterintuitive about this result. We usually expect education and urbanization to be associated with a leveling of regional dialect features and an adoption of a more generic standard. But more contact with outsiders can also lead to a desire for a stronger distinctive identity. As Tillery and Bailey say, it might be
that the form is used by native Southerners — especially those who live in areas with large numbers of non-Southerners or who are in contact with non-Southerners in their work — as a badge of local identity, that is, as a way of affirming local values in the face of widespread migration into the area by outsiders who (often unwittingly) pose a threat to local values.
So the answer to the question of whether singular "y'all" exists has to be a "yes." As for the question "exists for who?" — well, I may be a clueless Northerner, but I have sense enough to step right over that one and show myself the door. Later, y'all!