User role permissions per language Drupal 8 supports Multilingual (i18n) in core. I was wondering, is it possible to restrict users to be able to add/edit content for only one specific language?
Yes, you can use hook_node_access to control access to add/edit for the node. 

For example, you can check the value of:

$language = \Drupal::languageManager()-&gt;getCurrentLanguage()-&gt;getId();


and return the access result accordingly