In which language will the user receive emails/notifications from the system?
Each user in the system has a language settings in their profile:

Users can change it via the languages switcher at the top:

In Qmarkets we have the option to set the users' languages based on their location/country.
For example -
Users that their country profile field = Turkey, will be assigned to the TR language.
User that their country profile field = Italy, will be assigned to the IT language,
And so on.
If you wish to set this option - please contact your CSM.