whoever vs. whomever

I never know which one i should use. whoever or whomever. so usually i just guess.

The rule is: him + he is whoever
and: him + him is whomever

Example: Give the ball to whoever/whomever asks for it.
he asks for it. so give it to him.
Therefore: give it to whoever asks for it.

They will accept whomever/whoever she wants.
They will accept him. She wants him.
him + him = whomever


websight