friendica.dunkelangst.org

How to change the language in Friendica?

I still can't switch the language of my friendica generally to English. There is no need for another language, because English is the world language.

Also when I use an English browser in debian GNU/Linux my site is still in German. Anybody an idea to help me?
30.1% english, 22.9% pidgin, 19.2% norwegian