Just a little note about Facebook... a few months ago I started writing some of my status reports in French and then a day or two later, everything automatically changed into French and it totally freaked me out! (FB maybe detected something... I don't know. Maybe it's too smart for it's own good). I hadn't changed any settings but I quickly went to read about how to change it back into English.
And now, I've purposely changed the language setting to French and it really helps! So try it if you dare... (you can easily change it back if it's too scary) ;)
It's really easy to change. The option is in the bottom left hand corner.