From canon... Testing my memory here, but there's a bit in Ordinary People where he flies to France, Belgium and I think it was Japan to get stuff for Lois. So we could add French, Dutch/German/Flemish (depending where he went in Belgium) and Japanese to the list.

"It means never having to play it cool about how much you like something. It's basically a license to proudly emote on a somewhat childish level rather than behave like a supposed adult. Being a geek is extremely liberating."- Simon Pegg