1. That's right. 2. That's spot on. 3. You've hit the nail on the head. / You've nailed it. 4. I suppose so. (use this when you agree, but you are not completely convinced) 5. I'm afraid you're right. (use this in response to bad news, to say the bad news is correct)
Incline your head back, rest your chin on your palm, and pull your jaw open.
Say Ah! (you can mime it).
Grab your chin with your thumb, index and middle fingers.
Stretch it left to right. This exercise will help if you have been hit to the jaw (e.g., knocked-out in boxing).