Well for me with 16.04.1 it was not working until I add locales-all package.
But still, language-settings allows me only to add english language it seems. If I try to add french-canada, utf-8 (or pretty any non english) it does not appears in the list, and do like if it was never added.
BTW, I see in bodhibuilder Settings: "Locales to includes" but did not cared up to now to write something there. Guess I would prefer if it was "Locales to excludes" :-) Not sure if need full format... or what. Would "fr,en" be valid?