Agreed with the polite. I live in a city in Flanders where probably 70% of the people are fluent in English (they tell me TV and movies have a lot to do with it), and even then I start off with "Dag, sprekt Engels?" if I know I'm not going to be able to blunder through in Flemish.

And I hear you on the tonal languages thing. A couple of my fellow linguistics students in grad school were from Shanghai, and they tried to teach me tones. Apparently I am tone deaf, since I failed epically. I still have no idea what I said, but apparently it was really funny.