Add New Language
Go to More > Languages menu item.
To add a new language, you need to click the + button given in bottom right corner of the screen. This will open a popup (as shown in following figure). Here you can enter name of the language and a machine name. You can also upload a flag image.
Now, clicking the SAVE button will create this new language and will save in database. And this will start showing in the list of the languages.
Note:
By default the newly added language will have copy given in English language.