Based on an Actual Conversation:

Morgan: Do you know about Berlioz?
Michael: I know he's a composer, otherwise je ne c'est qua.
Karen: What does that mean?
Michael: Berlioz?
Karen: Jen nay say qua?
Morgan: I don't know what.
Karen: I don't know either. What does that mean?
Michael: I don't know what.
Karen: The French you just said.
Michael: Je ne c'est qua?
Karen: Yes, that.
Michael: I don't know what.
Karen: But you just used the phrase.
Michael: Yes, I don't know what.
Karen: The French phrase.
Morgan (getting amused): Je ne c'est qua?
Karen: Yes.
Morgan: I don't know what.
Karen: Neither of you knows what it means?
Michael: Yes, we both do.
Karen: And?
Michael: I. Don't. Know. What. Ne comprenez-vous pas?
Karen: What did he just say?
Morgan: Don't you understand?
Karen: No, I don't.
Morgan: That's what he asked.
Karen: What?
Michael: No, don't you understand?
Karen: Of course I don't understand! I don't know what ...
Michael: Je ne c'est qua.
Karen: Argh! I don't know what! Don't you understand?
Both: Elle l'a fait! (She got it!)