German and Czech ATC are highly competent and professional and speak English, but remember, it’s not their native language, and they’re used to speaking English with other non-native speakers. Americans, they feel, tend to speak colorfully or offhandedly, which makes it difficult for them to understand you – even if you’re saying what you feel are relatively simple things.
What they say to you can sometimes sound convoluted (and there’s the near universal German tendency to call your Cessna a “Chessna”), so be on your toes. Halfway down the runway on take-off in Augsburg, for example, the controller without preamble came back with,
“…and if you appreciate, on your way to [checkpoint] Oscar, you may continue with climb, and until passing with three thousand.”.
Ah. Don’t turn left towards Oscar till you reach 3000 feet. I appreciate!.
Speak more slowly than usual, and be as precise as possible. Remember, too, that it’s required you repeat every piece of information given: if they say, “Clear to land, runway 07, QNH1013, wind 100 at 12 knots”, that’s what you say back!