Questions about translating Discourse

Which are the methods for debugging a translation?

How can I install my translation from crowdin so to test/improve it?

Also, can you tell me when the translations are updated to the upstream and how to update it to my Discourse installation?

Also, I see that we have no more sub-languages, like pt-pt or pt-br, like it was in transifex, but only pt now. How this is being handled now?

Thanks in advance! (I am translating pt)