You can say that again

Meaning/Usage: Completely agreeing with a statement

Explanation: When you hear something you agree with, you can simply agree. But if you completely agree, then you wouldn't mind hearing it again. This is not literally telling the person to say it again, but to tell the person that you "really" agree.

A: "Britney Spears is so hot!"
B: "You can say that again."

A: "It was a long year. We accomplished quite a bit."
B: "I'm just glad that we're almost done."
A: "You can say that again."

Other Common Sentences

"I hear ya."
"You got that right."
"Damn right."