Hi Torsten,
Do you mean that you you’re using the Community Events add-on, and for English speakers you’d like the “Add Event” form to be in English, but for German speakers you’d like it to be in German?
If so, this is unfortunately not possible with the plugins by themselves. You might be able to achieve it by using a multilingual-site plugin like “qTranslate” or something similar, though I don’t have a specific recommendation for such a plugin.
Sorry to disappoint, and if I’m misunderstanding your request, I’m sorry about that too! 🙂 If that’s the case, elaborate on your question in a bit more detail and we’ll try to offer a better answer here.
Cheers,
George