@developer I'm not sure, but I think it's not possible right now. So, if it is not already implemented, this will be a nice feature request.

I do know that there are some ideas for built-in multi-lanaguage support. I will keep this post updated on any progress.

This would be great. The only solution I found was to keep each blog with one (different) language (and use the Pages and Intro-Cat to the menus). But with this option suggested by @developer would expand the possibilities, a lot, at least in my case. Then the whole page would be in the language the user chooses and the collections would keep the content organized (and not just the 'page's posts and 'intro-cat').