Out of curiosity, is there a limit to how much you want us to post? Such as if two people get caught RPing together, or in a conversation or something?
Sorry, yes. The common tongue is Keatish, but not everyone actually speaks it. With that being said, all of the PCs speak Keatish and the language of their homeland. Your character is from Velmark, so she speaks Velsh. DarkJester's character is from Haerland so he speaks Haerlandic, etc..
EDIT: @DarkJester, That's fine, man. Just use your judgment.