Half of everyone in Germany can speak English. It's mandatory to learn in schools. In Berlin that percentage is even higher. So it's no obstacle. And they don't want to limit the visibility of the protest to only Germany.

Germany is one of the more native-language-enforcing countries in Europe. I've been to Slovenia and half of everything is actually written in English, unlike Germany or France where everything's written in the local language.

Because they want to have the eyes of global press on Germany