Adding Primary Language
To add primary language,
Go to Settings.
Add a Primary Language.
Enable it using the Status toggle.
Once added, Primary language cannot be disabled or modified. The primary language content will always be visible to users of that locale and also to those users whose locale language is not yet added or enabled.
Adding Other Languages
To add more languages,
Click Add a language. A pop-up box appears.
Select the language from the drop-down.
Click Add language.
Enable the newly added language using the Status toggle.
By default, newly added languages are disabled. You have to enable the languages to use them.