If you don't know how to speak in English, at least please use pictograms! Please note that the whole world does not consist of little Germany!
Using "please" with confrontational statements like those does not make them any more polite.
And please note that proper English would be "speak in English" and "[not] the whole world does not consist[s] of", if you already insist on it being used.
It's possible to be more friendly in requesting support for English, while still conveying the fundamental nature of it, e.g., "Please at least add pictograms if you struggle with English." No need to go further.