You can delete a language you no longer need. If you don't want to delete a language, you can disable it. See Enabling or disabling a language
  1. Go to User Experience > Languages.
  2. In the list, locate the language you want to delete.
    Note:

    You cannot delete the provided languages or the default language, but you can delete any custom language.

  3. On the right side, click the More Options menu (⠇) and then click Remove.
  4. In the confirmation message, click Delete.