Don't judge a book by its cover.
Don't judge a man by his apperance.
What's your new teacher like?
Have you met her? What's she like?
What kind of impression did he give you?
What kind of a guy is he?
What was your first impression of him?
I can't tell what people are like just by looking at them.
He's got nerves of steel.
He's very cool under pressure.
He doesn't lose his cool easily.
He gets angry easily.
He has a short temper.
A: So how was your blind date the other night?
B: Not that great. I mean he was nice and all. But there was something about him.
A: What? You make him sound like he was hiding something. Was he shifty?
B: No, he just seemed too nervous, like he had something to hide.
A: Maybe he was just nervous about the blind date.
B: That's what I thought too, at first. But all through dinner and the movie afterward, he was never relaxed. It was a bit odd.
A: Maybe he's just a high-strung person. Or maybe he's actually married.