Is it her? No, that is wrong. It should be Is it she? The meaning is clear if we reverse it and say Her it is, which is plainly wrong, whereas She it is, is plainly correct.
Or to put it another way, Is it her? begs the question of ‘Her’ what? Her dog, for example?
None of this is my natural language. I make the mistake all the time. Tamara is a much better speaker of English and she gets it right all the time.
So we were talking about this mix-up, and how people speak. Suddenly, in a blinding flash of insight, I noticed something about the English language.
We, wrongly, say Is it him?, whereas the correct language is, Is it he?
And that is when it struck me that we say her and her dog.
But we say him and his dog.
Females only get her.
Males get him and his.
Why is that?
Leaves on the ground in Cambridge, yesterday, so beautiful in their place in the universe.
They grew on trees
They fell from trees
If the worms didn’t eat them
They’d be up to my knees