Wit, unker, Git: The lost medieval pronouns of English intimacy

https://www.bbc.com/future/article/20260408-the-extinct-english-words-for-just-the-two-of-us

Wit, unker, git: The lost medieval pronouns of English intimacy

Tales of love and adventure from 1,000 years ago reveal a dazzling range of now-extinct English pronouns. They capture something unique about how people once thought about "two-ness".

BBC
Also sad is the fact that “you” is now used for “thee” and “thou” and such. The older variants could distinguish between “you” plural and “you” singular
W'all have got y'all for plural you.

You, y'all (small close group), y'all all (larger, further group), and "all y'all" — Southeast Texas (coastal) dialect form that showed up about 25 yrs ago. I suspect it might've been there all along, but only became acceptable at that point?

Another 100+ years, and this'll be some solid grammar.

Don’t forget you’uns or yinz!

I struggled with this when I was a school teacher. English lacks a good way to clarify you are addressing a group vs one person, which comes up a lot in a classroom. “Class, you…” is clunky, “You guys…” has obvious issues, and y’all or any other contraction is generally considered bad grammar. I generally went with y’all. Kids would laugh about it, but that seemed to help get their attention.

Surely, you knew all of your students' names and if you were addressing one person, you could've used their name. Addressing the class as merely "class" seems adequate as well. I'm having a hard time thinking of a situation where you are forced to use "you" ambiguously.
What if you're addressing part of the class, though? Like "y'all in the back, you need to get back to your work".
"You in the back" has the same level of specificity. Other options include (again) naming names or calling out a more specific location "You in the back row".
No, because "you in the back" could refer to just one person in the back, instead of several. So "y'all in the back" is more specific. (Of course names are an option in this context.)

(Of course names are an option in this context.)

Yes, this is a case where you aren't forced to use "you" ambiguously in that context.

No, because "you in the back" could refer to just one person in the back, instead of several.

If you meant to address one person, you'd have said that one person's name, instead of voluntarily introducing ambiguity to the situation. Context & body language also makes this obvious. If you meant one person, you'd be making eye contact with one person instead of a group of people, etc. Students also know if they're paying attention or not. "The back" is not a specific area.