"I said "y'all", which is plural"
Well, I'm from Washington state but I spent a number of years in the South (Virginia, Georgia, Louisiana) and I was taught that "y'all" was singular and "all y'all" was plural. Was I taught wrong?
"Y'all" is a conjunction of "you all" and "all y'all" is not only redundant but seldom used in my experience. Have you seed the error of your ways? ;-)