Who have you invited?

post them here

Whom, not who

It is still grammatically correct

What are you talking about

How to use who and whom correctly? The answer is simple: If you can replace the word with “he” or “she” then you should use who. However, if you can replace it with “him” or “her,” use whom.

See? "Whom have you invited" can be replaced by "You have invited him/her".
Who have you invited -> You have invited ~~he/she~~ .

My friend

I invited my friend