Some Contractions Aren't Like Others, Y'all
A Google search for a nonstandard spelling of a chiefly regional word yields 13.2 million hits. That’s for ya’ll (in quotation marks). The y’all spelling, preferred in all my dictionaries and usage guides, gets 38.6 million Google hits.
I tweeted about the preferred spelling yesterday evening, and it struck a nerve:
The contraction is for “you all” (not “ya all”), so it’s “y’all,” not “ya’ll.”
The ya’ll spelling seems to be a pet peeve of many, with responses to my tweet filled with exclamation points and words of encouragement.
But Matthew Gordon (@anotherlinguist), a linguist and expert on dialects at the University of Missouri, pointed out that the contraction didn’t necessarily start with you all. Linguist Michael Montgomery traced its origin to Scots-Irish settlers in the South, who used ye aw for the plural of you. Montgomery has pointed out that it is used in ways that don’t match the longer form, you all.
And ya’ll is not indefensible. It could be considered a contraction of ya all, which is how it sounds when pronounced slowly (but I'd call that simply a phoenetic spelling). Garner’s Modern American Usage, citing Montgomery, points out that y’all is the only contraction in which the stressed word is the one that is contracted.
There is considerable debate about whether y’all can properly be applied to just one person. This may be a dialectal difference. It does stretch logic—the all in you all makes it plural, so there seems to be no basis for the singular y’all, which is covered quite nicely by the word you. But there is no denying y’all is commonly used to refer to just one person.
And then there is all y’all, a seeming redundancy, made necessary on occasion for clarity because of the singular y’all.
Most dictionaries and usage guides don’t bother to criticize y’all, though it isn’t likely to be seen in formal writing. Neither is you all. However, y’all is fine for when you just doesn’t seem to do the job as a plural. Sometimes, we want to be clear when we say “you come with me” that we mean either a specific person or everyone within earshot. Youse and yinz are other forms that satisfy the need for a second-person plural. But they haven’t caught on in formal text, either.