Is a reverse tree hard
It probably depends on your knowledge of both languages. Assuming English is your first language, and you do English for French speakers for example, the biggest issue would be if you started making grammar mistakes in French. Also, the more study you’ve done off of Duolingo (in classes, etc), the higher your fluency would be, and the easier it should be if they started using synonyms etc.
It’s also going to be significantly harder if you undertake something like learning French and Spanish only on Duolingo, then attemping a Spanish tree for French speakers. Or if English isn’t your first language and you try to do English for speakers of another language you’re studying.
I’ve tried English for Arabic speakers for example, (I know a decent amount of conversational Arabic, but sometimes they use a weird word for something simple like boy, and I’ve never seen the word and can’t find it online.
It may be difficult, but it’s possible. You may not be able to test out of skills as much as you’d like, and you’ll probably get confused at times, but if you’re patient its fine. Best of luck(:
It's definitely worth doing (thought I haven't done mine, as I'm waiting for tree 2.0) as it introduces more words, and it's stricter (ie it won't allow you to make as bad spelling mistakes in what it thinks is your native language)
It also uses more words for the same things, just think how many ways you can write the answers in English, but you always do the same in the language you're learning, it becomes the other way around.
I am not sure about the spelling mistakes. In the trees I am doing, I have noticed that the French trees (both directions) are definitely fussier than the English->Italian one. Due to my Spanish, my Italian spelling is fairly hopeless, but Duolingo calls most of those typos instead of rejecting them.
Maybe you're right, I feel it's pickier when I do it though. I think it's just as picky in the other direction, like "hosue" instead of "house" has caused me to get many questions wrong, but I because I'm native English, I don't make that mistake. Would be interesting to know how it's actually done
A little harder, but that's good! Challenging yourself is what makes and keeps DuoLingo interesting! You might also want to try other courses with French as base language, such as Spanish, German or Italian, that can be a very interesting approach to the way you use and think about French.