when i was in middle school, I decided to study Japanese on duolingo. recently I've switched to other resources and immediately realized how bad my japanese still is. for context: I've been doing this for 5-6 years and I would estimate my skill to be <N5. the past year I started using other resources (e.g. textbooks), and I am learning at a faster rate. the problem with duolingo is, that they dont explain concepts and expect you to figure it out. at some point it started repeating words and introducing them as a "new" word. it treats different conjugations as different words as well.
another problem, is that it is in their best interest to teach you at a slow rate, so you stay on the app for as long as possible. in the beginning it was working, but as I progressed, I got to parts of the course most people dont get to, and actually learning japanese felt like an afterthought.
one more problem is that it often teaches words without Kanji (eg instead of 難しい it teaches むずかしい)
by chicken_is_no_weapon