Setting default language on Mattermost/Framateam

I am trying to use Framateam as a replacement for Slack for a Learning Circle ( taking place in Boston (MA, USA). The main difficulty is that the default language for the interface is in French and participants, who don’t speak French, have to navigate it in order to change the language to English. Is there a way to set the default language for a particular group/team instead or each participant having to do it?
Thank you for your help!

Apparently no (apart if you install your own instance, of course).
But they have to change it once normally :
(Menu) ≡ → Paramètres → Affichage → Langage

Thank you for clarifying!