I was wondering whether the selecting one of the languages in the interface locale dropdown in the admin page should change anything ?
It didn't seem to do anything on my installation (
clone from github running in ubuntu instance on AWS).
Magento Stack Exchange is a question and answer site for users of the Magento e-Commerce platform. It only takes a minute to sign up.Sign up to join this community
That is because there is no official language translation for Magento 2 yet.
There are only stubs for 6 languages. For example, for German language: https://github.com/magento/magento2/tree/444e252d40b3a5d5cca3468a9819743af8ed3513/app/i18n/magento/de_de https://github.com/magento/magento2/blob/444e252d40b3a5d5cca3468a9819743af8ed3513/app/code/Magento/Backend/i18n/de_DE.csv
As you can see, any translation is absent.
You can do language package by yourself, see the documentation.