In the first episode, "Winter is Coming", of Game of Thrones, after the wedding of Daenerys and Khal Drogo there's the following dialogue:
Khal Drogo (Seeing Daenerys' tears): No.
Daenerys: Do you know the common tongue?
Khal Drogo: No.
Daenerys: Is "no" the only word that you know?
Khal Drogo: No.
What is the meaning of this conversation? What does it convey?
Note: NO SPOILERS please - I have just watched the 1st episode.