Per user language selection I need to do the following on my Drupal 7 site:


Anonymous users should see the website in Ukrainian (I mean not the content, but the elements like "Login", "Register" etc.)
Administrator (the user with all permissions) should see the admin panel in English.
Editor (custom created user that can create pages) should see his admin interface in Russian.


I suppose it can be done with a per-user language setting, but I cannot find how to do this. I already have all the translations installed.
"Follow the user's language preference" option in Drupal language preferences does the trick.