How come German has such a bigger tree than all the other languages and when can we expect bigger trees for other languages mainly Dutch?
Actually, Norwegian is the biggest tree. I think it has 122 topics and 500 lessons.
The German tree might be bigger because it was one of the first courses to be released on Duolingo for English speakers, there are more words to learn, or there is more grammar to learn.
I don't know German, but I hear it's complicated. The U.S. government classifies it as a level 2 language for english speakers to learn, while pretty much all other Germanic and Romance languages are level 1. Also, I just can't resist saying this about the title of the discussion: PHRASING :D
Simius, one of the Dutch course team, says that Dutch 2.0 is ready to go, and they're waiting for the programmers to get back to them: https://www.duolingo.com/comment/22145163$comment_id=22196419