It's not consistent. I believe in some countries it's all English. In Germany, big airports are English, and small airports are German. In the couple of smal

It's not consistent. I believe in some countries it's all English. In Germany, big airports are English, and small airports are German. In the couple of small airports I've flown out of in France, it's French. I've heard of some countries where the controller will speak to you in whichever language you speak to them, which can lead to issues with situational awareness if you're the only one on the frequency speaking English and you don't know where all of the other planes are.