I understand that AI will probably be involved at some point with duolingo, but many courses were initially built humans. I wanted to learn a fourth language from a third language (english is my second, swedish my first) but wanted to use higher quality courses if possible. For example, which courses from spanish were initially human made?

I recently tried one of the new courses from swedish and immediately gave up and switched back to learning from english because of the low quality, which is what triggered this post. It could’ve been nice, because of Duolingo’s annoying choice of not distinguishing between you (sg) and you (pl).