The confusion comes from the fact that in English, the plural of "you" is "you". This is clearly inadequate and confusing, and virtually everyone more than 150 miles from Buckingham Palace recognizes that it is (those who live within 150 miles of Buckingham Palace seem mostly to relish ANY obfuscation the language causes).
In southern states, this has resulted in "you all" and "y'all", whereas in parts of the rust belt the proper form is "all youse", often contracted to just "youse".
Both forms are, of course, painful to those who speak the "pure" version of the language. Most of those who are stuck without a decent plural form of the word seem to feel that it serves them right.