Every add-on is capable of being translated, yes.
Yes and no.when you change your default language (with some combobox with many languages) then you see other posts in that newly chosen language?
XenForo has language packs which translate XenForo in your desired language. You can have more than one language installed.@Adam Howard
it is not about google translate posts into different languages
it is about preparing 2 posts in different languages (e.g. english and german) and posting it on main page.
When someone with default german language comes to the site he will see only posts in german (not auto translated but dedicated to people from Germany)
If I understand how XF works it would need 2 licences and some kind of integration under one portal that can swich between forums but have one user base. But I might be wrong
Simple Portal could do this with some small changes (via an additional addon)If any from portal add-ons support multiple languages(front page with news only on your language, news threads in different language forums etc)?