Here's one I've been thinking about, when you are playing chess, does the discussion get translated to your own language or do you have to know English? The same goes for everything else.

Je ne peux pas vous comprehendre. Qu'est-ce c'est que vous souhaitez exprimer?

huh?

  wakariyasui

Huh?

You have to know english.  I suggested awhile back that they have more than one language because I play with several people from different countries.  I was informed that at this time english was the only language and there was no plan for different languages now.  I replied that possibly in 3 to 5 years it would be a good idea.  They are still trying to work out many other details and bugs and requests that have a higher priorty.