Originally Posted by
The_Bouncer
I think France and China are the exceptions, but only when flying domestically. Scandinavian and Dutch pilots certainly speak to their own ATC in English, as it is considered easier to stay with one language than constantly switch between two (as a speaker of several languages, I can confirm that it is).
That's why I said some areas. In France, there's a clear tradition of preferring to speak French and of "defending" their language. Other exceptions might be large areas where people would be somewhat less comfortable with English, so certainly not Scandinavia or the Netherlands. I could imagine Russian pilots speaking to their ATC in Russian in addition to the example of China (where I would think that Mandarin, Cantonese, and various local variants/dialects would be very confusing).