Bernadette: Hey, Bert, what are you dressed as?
Bert: I'll give you a hint. My work in seismic refraction measurements and-
Bernadette: Hey, Stuart, what are you dressed as?
Stuart: I'm a butterfly.
Bernadette: Did you steal those from Halley's "let's pretend" box?
Stuart: I'm gonna put them back.

Stuart: Oh, Sheldon, I'm afraid you couldn't be more wrong.
Sheldon: More wrong? Wrong is an absolute state and not subject to gradation.
Stuart: Of course it is. It's a little wrong to say a tomato is a vegetable, it's very wrong to say it's a suspension bridge.

Howard: Hang on, I know a place where you could you stay and earn some money at the same time.
Stuart: Great!
Howard: I just have to warn you: it will involve humiliation, degradation and verbal abuse.
Stuart: So, what's the catch?

Bernadette: Hey, Stuart.
Stuart: *startled* Hey.
Bernadette: Sorry, did I startle you?
Stuart: Yes, but at this point pretty much any customer does.

Sheldon: Well, I can understand how that would make someone irritable.
Howard: Interesting fact: "irritable" comes from the Latin, "susceptible to anger."
Sheldon: Just because I used a word doesn't mean I want its etymology.
Howard: Interesting fact: "etymology" comes from the Greek word-

Leonard: Oh, my God, you look amazing.
Raj: I find you guilty of murder, because you are killing it.
Howard: (imitating Sheldon) Well, technically, the Supreme Court wouldn't determine a defendant's guilt or innocence in a criminal matter. They could only reverse or revamp a jury's conviction based on a constitutional or statutory issue.

Howard: You're sitting in my spot.
Sheldon: You don't have a spot. What is wrong with you today?
Raj: Maybe he's cranky because he's off his bathroom schedule.