My grandpa is real sick and my grandma tries to help him walk again but he never listens, what should I do?

I try to help them, and I try to make grandpa understand, but he only listens a little bit and then only seconds after I finnish he seems to see it only as a annoyance. they also work together for a few moments, then he doesn't listen and it always go back to them fighting, I try my best but almost every time I'm home they always fight. Is there any way I can help at all?