Correct me if I’m wrong of course ...
In Middle English, I’m told, thou was the 2nd person singular nominative pronoun with thee as the corresponding objective pronoun. Ye was the 2nd person nominative plural pronoun, and you was the 2nd person objective plural pronoun, with both of these plurals also serving as honorifics.
Examples from The Canterbury Tales:
“Thou hast a vain imagination”
“The Miller is a churl, ye know well this”
“I warn you all this rout”
(I also found “Acquit you now, and holde your behest, then have ye done your devoir at the least”, where you appears to be a reflexive pronoun.)
Things appear to have changed by Shakespeare’s time. Thou and thee remained the same, but you had come to be used for both nominative and objective. Shakespeare used “you” in heaps of cases where only one person was being address but I suppose it might have been honorific. Ye seemed bolted to plural nominative.
From Hamlet “But, you must know, your father lost a father” (You as singular (honorific?) nominative pronoun)
From Hamlet “You know the rendezvous.” (You as singular (honorific?) nominative pronoun)
From Hamlet “We’ll teach you to drink deep “ (You as singular (honorific?) objective pronoun)
From Hamlet “He will stay till ye come.” (Ye as plural nominative pronoun, speaking to attendants)
From Macbeth “that indeed which outwardly ye show?” (Ye as plural nominative pronoun, speaking to witches)
Late 18th century American novels such as “Charlotte Temple” and “The Coquette” make scant use of “ye” or “thou”, using “you” in most circumstances.
But in Moby Dick (1850), Pip recites the following from a book of grammar: “I look, you look, he looks; we look, ye look, they look.”
You was the singular nominative pronoun, ye the plural nominative pronoun. Thou, from Pip’s grammar, was gone.
Various characters in Moby Dick say “thou” but from the context I take it this is meant to be old fashioned. I would probably have taken all the instances of “ye” to be intended as old fashioned as well, but the fact that Melville has placed “ye” in a book of grammar suggests to me that it was a current, common pronoun when he was writing, in 1850.
So was “ye” really a standard form in the mid 19th century, such that you’d expect it to appear in a book of grammar?