I use ub18.04 in german. In the settings some things seems to be broken. there are a mix from german and english words.
sorry for my bad english. 
Little surprised. This is a GNOME app called gnome-control-center… So translations are done upstream.
Suggest raise an issue on launchpad and offer if you can to do the translations. The bug triagers will point you in the right direction.
ubuntu-bug gnome-control-centerIs your region & language set to German?
If it is set to German then this still sounds like a bug and you should report it to launchpad
Fix has been released in the last week or so - just make sure you are up-to-date