Raj: No offense to her father, but he's not an MIT-trained engineer. Thinking and building is what you do.
Howard: MIT's motto is "Mind and Hand," which just so happens was also my motto as a lonely teenager.

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Josh: So, I have to ask, was the robot sexy?
Howard: It was actually just a mechanical hand.
Josh: 'Cause that's all you need, right?
Howard: You are my brother.

Sheldon: Sheldon Cooper does not cry.
Howard: That's true, you'd rust.

Leonard: I would pull this car over and kick you out, but if Penny dumps me, you're all I got.

Sheldon: Amy is free. She had a harp lesson on Saturday, but it got canceled. Boy, when you take an interest in people, you really uncork a geyser of nonsense.

Bernadette: Things going well with you and Sheldon living together?
Amy: Better than ever. He asks about my day, takes an interest in my life. He's like my boyfriend in college, except he's real, so people can see him.
Bernadette: I've been seeing him for years. I'm still not convinced he's real.