I lived in Germany for a bit. While there I really wanted to learn to speak German properly, but when I first arrived my spoken German was pretty awful. Since many Germans speak English pretty well and could evidently tell from the way I was pronouncing things that I was an English speaker they would often switch to speaking English with me mid-conversation. This annoyed me because I'd gone to a lot of effort to move there, was trying my best to learn the language, and this was clearly hindering my efforts.

So I came up with a plan. Whenever a conversation would switch to English in this way I'd lay on a really thick accent, use lots of slang and idiomatic phrases, and generally try and make things difficult for the other person to understand. The result was often that the other person would look puzzled and the conversation would switch back to German. Eventually I learned how to pronounce things in a way that didn't immediately betray me as a foreigner, but this trick helped a good bit in the beginning.