After updating to latest version, language switched to Spanish and I found no way to turn this back to english. Help!
You can navigate to System Preferences, select Language & Region, then click button and add Core Shell with Language set to English.
"spanish" was added to macOS which was not there before, whole system running in "german".
After removing "spanish" CoreShell now is english, great.
Anyway it should not install/activate Spanish in any way... happened with last update