You are right
Yes, that’s right. You’re quite right.Yes, that’s correct. That’s spot on.
I’m afraid you’re right. That’s right. You can say that again. Absolutely.
You’ve hit the nail on the head. Yes. You’re so right (there).
I suppose so. You hit the nail on the head. Indeed.
(use this when you agree, but you are not completely convinced)
(use this in response to bad news, to say the bad news is correct)
Isn’t that true! (Rarely: Ain’t that the truth?)
Isn’t that so! (Rarely: “Ain’t that so!)