Annoying corruptions of English.

[toothache]

I get, "can I lend" instead of "could I borrow...?"

Do you find “May I borrow” acceptable?

[toothache]

The problems arise because most teachers themselves do not speak correctly,

When I taught in Yorkshire, in Middle school. (9-13), the Head of Year 1, who was also Head of English and later Deputy Head said “I aren’t” meaning I am not or i’m not. As a mere scientist, it really grated on my nerves.

[Mr Saxon]

Do you find “May I borrow” acceptable?

I prefer "could you lend me? " or "could I possibly borrow?"
I associate the word May with either a month , the tag line of the Star Wars series or that terrible woman who's in charge of our country and making a mess of Brexit