Oliver Queenan: Do you have any idea what we do in our department?
Billy Costigan: As a matter of fact, I do. I...
Dignam: Let's say you have no idea, zero, none. If you had an idea about we do we wouldn't be good at what we do now would we? We would be cunts, you callin' us cunts?
Ellerby: Go fuck yourself.
Dignam: I'm tired from fucking your wife.
Ellerby: How is your mother?
Dignam: Good, she's tired from fucking my father.
Lazio: Do you have anyone in with Costello presently?
Dignam: Maybe. Maybe not. Maybe fuck yourself.
[after Costigan has quoted Nathaniel Hawthorne] Pfft! What's the matter, smartass, you don't know any fuckin' Shakespeare?
Police Camera Tech: Who the fuck are you?
Dignam: I'm the guy who does his job. You must be the other guy.