Stephen: You said you ain't know him.
Broomhilda: Huh?
Stephen: I said, "You said you ain't know him."
Broomhilda: I don't.
Stephen: Yes, you do.
Broomhilda: Mister Stephen, I don't.
Stephen: Why is you lying to me?
Broomhilda: I ain't.
Stephen: Then why is you cryin'?
Broomhilda: You scaring me.
Stephen: Why is I'm scarin' you?
Broomhilda: Because you're scary.
Django: Django. The D is silent.
Dr. King Schultz: How do you like the bounty-hunting business?
Django: Kill white people and get paid for it? What's not to like?
Django: They caught my wife, and sold her. But I don't know who to.
Dr. King Schultz: That means we visit every plantation until we find her. And once the final Brittle brother lies dead in the dust, I am going to give you your freedom. And I'll take you to rescue your wife.
Calvin Candie: Gentlemen, you had my curiosity. But now you have my attention.
Dr. King Schultz: Do you know what a bounty hunter is?
Django: You kill people, and they give you a reward.
Answer: Django and Schultz killed some of Big Daddy's farmhands, and he wasn't going to let a freed slave kill some of his workers. Schultz knew Big Daddy would come after them for what they did. Plus Django would never let go of a chance to kill a slave owner who was trying to kill him.