Try this link:
I or me
Interested in Language
When I say "It is me who is trying to help."
How about "It is us who is/are trying to help."
Am I correct re the first sentence?
(1) You have asked a great question.
(2) According to one scholar (Professor George O. Curme), the
"correct" answer is:
It is I who is trying to help. That is: It (who is trying to help) is I.
BUT today almost all books now say that the "correct" way is:
It is I who am trying to help.
(And, of course, most native speakers say "It is me." Many teachers
now accept "It is me" as correct because so many native speakers
actually speak that way.)
Nevertheless, if you want to speak "perfect" English, you might
consider saying/writing "It is I."
Regarding your second sentence, then:
(a) It is we who is trying. = the "correct" way that people
no longer use.
(b) It is we who are trying. = the "correct" way that most
people refuse to use.
(c) It is us who are trying. = the "correct" way nowadays.
As a rule of thumb (don't ask what that is!) 'I' and 'we' are the subject of the verb, whereas 'me' and 'us' are the object of the verb.
For example, My friend and I went to the cinema.
Her parents invited my friend and me to their house.
We went to the cinama.
Her parents invited us to their house.
Hope this helps a little.
Uncle M (not a teacher)
In It is me, me is actually the object of the verb too. That's why this issue has been brought up so much, without a simple answer provided.