George Little: Maybe we should go home.
Mr. Little: Why?
George Little: I'm not wearing my lucky underwear.
Mr. Little: You don't have lucky underwear.
George Little: Well, maybe we should get some, and then come back for another race.
Snowbell: I can't believe I'm arguing with lunch.
Stuart Little: Snow, where are you going?
Snowbell: Oh, I gotta yawn, stare at traffic, lick myself. And believe me, that could take hours if you do it right.
Snowbell: You think you could help me?
Smokey: Consider it done.
Snowbell: Thank-you Mister Smokey sir, how could I ever think you?
Smokey: Don't worry Tinkerbell, anytime.
Snowbell: Tinkerbell! Ha Ha, He called me Tinkerbell! You're a funny guy.
Smokey: Yeah, whatever. house cats, Sheesh.
Snowbell: I lied, okay? Welcome to Manhattan.
Mrs. Little: Is he going to be all right?
Dr. Beechwood: Well, a lad that size swallowing all that detergent. Amazingly, I think he's gonna be fine. Also, he's very clean.
Mrs. Little: He hates us.
Mr. Little: We've never been hated before.
Anton, the stuck-up bully: Gee George, you all done crying?
George Little: Yeah! Are you all done being a jerk?
Anton, the stuck-up bully: No.
Stuart Little: So, what do I call you?
Mrs. Little: Mom.
Mr. Little: And Dad.
Mrs. Little: We haven't told you the best news of all.
Mr. Little: You have a brother, named George.
Stuart Little: What do I call him?
Mrs. Little: George.
Race Spectator: Who is that mouse anyway?
George Little: That's no mouse, that's my brother.
Snowbell: Didn't your mother warn you that you shouldn't go out into Central Park at night?
Smokey: My mother was the reason you shouldn't go out into Central Park at night.
Answer: Since there no scenes of cats trying to communicate with humans, we don't actually know if humans can understand them or not. It may be that cats can communicate with humans, but simply choose not to.