How do I change the language via a terminal?

Edit two files:

  1. sudoedit /etc/default/locale:

    LANG="en_US"
    LANGUAGE="en_US:en"
    
  2. sudoedit ~/.pam_environment:

    LANG=en_US
    LANGUAGE=en_US
    

Logout and Login or Reboot.


In order to get back to English, I had to change my locale in 3 places:

  1. /etc/default/locale

    by running this command:

    $ sudo update-locale LANG=en_US.UTF-8 LANGUAGE= LC_MESSAGES= LC_COLLATE= LC_CTYPE=
    
  2. ~/.config/plasma-localerc and ~/.config/plasma-locale-settings.sh

    By going to my KDE settings / Regional Settings / Language

And reboot.