pronoun query

"Mary and I are friends."

Is this sentence grammatically correct? I say yes.

It means that "Mary is a friend; I am a friend." Correct?

Thanks.

 

Yes, it is correct. Is someone telling you it isn't?

 

Thank you.

 

It means you are friends with each other.

 

Mary and I are friends. <--WIN
Mary and me are friends. <-- FAIL
We are friends. <-- WIN
Us are friends. <--FAIL

The wins are wins for the same reason and the fails are fails for the same reason.

Mary and I killed Peter, Greg, and Larry.

Gruesome as this tale may be, and complex as the subsequent trial may be, the plurality of subjects and objects has no effect on whether they are subjects or objects. Mary and I are both defendants. Peter, Greg and Larry are all the injured (and in this case, deceased) parties. Both legally and grammatically.

[Mary and I] killed [Peter, Gred, and Larry.]

 

So WE (Mary and I) killed THEM.

And then THEY wanted vengeance on US (Mary and me).

 

If you can understand it, then it's fine.

 

Precisely.

 

Thanks, everyone.