[davidgh]

Agree.

“Ya’ll” is linguistically necessary in English since the word “ye” was deprecated.

A common alternative to remove ambiguity between singular and plural “you” in some parts of the US is “you guys”.

[rendall]

English has "thou", which was the singular second person pronoun, and "you" which was the plural second person pronoun, but also used as a more formal, polite singular second person pronoun. Through a kind of formality inflation, everyone started using "you" all the time and abandoned "thou". Contemporary standard English doesn't have a plural second person pronoun, but needs one, and so "y'all" (or "ya'll") is being used now in some regions.

[gnubison]

“Ye” is just the nominative case (like “I” vs. “me” being accusative), it has nothing to do with number. Thou/thee is the one with number.

[davidgh]

You have it exactly backwards. Thou is singular and informal, ye is plural and / or singular formal.

Ye is a second-person, plural, personal pronoun (nominative), spelled in Old English as "ge". [0]

The word thou is a second-person singular pronoun in English. It is now largely archaic, having been replaced in most contexts by the word you. [1]

[0] https://en.m.wikipedia.org/wiki/Ye_(pronoun)

[1] https://en.m.wikipedia.org/wiki/Thou

[gnubison]

Not sure how my comment is “exactly backwards” — it’s logically consistent with your (new) comment. My point was that, relative to you, ye makes a case distinction (nominative), and that relative to you, thou makes a number distinction (glossing over formal/informal).

We deprecated ye and thou, but it’s the latter that “requires” y’all, because only thou (relative to us still having you) distinguishes the number of people.

Edit: put another way, “thou/thee is the one with number” meant that reintroducing them would create a number distinction.

[wrycoder]

Then, there’s all y’all.