How do I transfer my progress?
So I started the French course two years ago (I think), and I've been working on it for some time. After that, I realised that the French course updated and now the course is split up into different parts. But it did not update automatically for my course, which is in the old interface. Does anyone know how to transfer your progress from the old French course to the new French course interface?
Not all the French courses have been updated. (It may be an A/B test.) If you get moved to a newer tree, Duolingo will attempt (valiantly) to carry your progress over. However, since there's a lot of new material throughout the course, what will probably happen is that you'll lose some crowns on many of your skills, and when you look at your progress on Duome, you'll find a lot of +4 lesson markings on skills that you had completed.
Duolingo didn't expand the tree by tacking a bunch of stuff to the end, they expanded the tree by adding new material throughout the course.
I hope this answers your question. If not, I'm not sure what your question is. I've never heard of two different trees from English to French (or any other pair of languages) in the same account at the same time.
Quote: But it did not update automatically for my course, which is in the old interface. Does anyone know how to transfer your progress from the old French course to the new French course interface?
Tree updates should be disabled until staff fixes their "tree update" code or find a new (better) tree design so people being migrated from tree2 or tree3 do not lose all their progress or crowns.
Feel free to go for tree12 (with or without Part1-8 grouping) in a new private browser window (no activity tracking) and new user account: https://forum.duolingo.com/comment/29069435$comment_id=29810695