My husband and I have a challenge going on. He was speaking to a client and used the sentence "It's not Jill and I who has to pay your mortgage." I believe he should have said "Jill and me" who's right?
'It's not Jill and I who have to pay your mortgage.'
The verb must reflect the fact that two people are concerned (Jill and I).
For example, you would not say 'We has to pay your mortgage.'
You must use 'I' as your pronoun, because 'I' is part of the subject.
'I' is a subject pronoun. 'Me' is an object pronoun.
A handy way to remember this is to mentally remove the other person (and any other non-essential detail) from the sentence and hear what sounds correct: 'I have to pay your mortgage,' or 'Me have to pay your mortgage.' Which sounds correct?
I do not know what your first language is, so it is difficult to give any further examples.
All best wishes,