May 17
I know some people will ignore this because it doesn't fit their “pretty boy” headcanon. But facts are facts. Comments are open if you want to talk.
In the comic 'Modern Warfare 2: Ghost,' it all kicks off in Ukraine, at a school in Lysychansk. Ghost’s taken hostage by Ukrainian terrorists -ultranationalists- and, damn, he gets them. He even tells his story to the Ukrainian kids, keeping them distracted. So yeah… he knew Ukrainian or Russian. No question about it.
Source: MW2: Ghost comic, Issue №1, Page №1