To change the language of your Backpack (settings, entries, navigation) you can do so by:
Click My Account Settings from the main menu.
Select Language and pick the language you would like your account to be in.
Don’t forget to select the checkmark on the top right corner to save your changes.
When you set a preferred language, all the text in the apps, emails, SMS messages, etc. changes to that language. This setting is on the user not on Profiles so you can view all the Profiles you have access to in whatever language you prefer.