How can I create a new language course which does not exist in Duolingo
I got an idea to create a course to teach people about literary Chinese（ancient Chinese 文言文), but I found that Duolingo didn't have this feature, which is very confusing. Can someone tell me what should I do?
If you want to make a course and be actively contributing to it, the first requirement is that you are fluent enough in Literary/Ancient Chinese to teach others. If you meet that criteria, you can apply here to make a course, and wait for Duolingo’s response; https://incubator.duolingo.com
If you don’t have enough knowledge of Literary Chinese to teach others the language, follow the directions on this discussion to vote for it; https://www.duolingo.com/comment/15014194
Many people also make unofficial lessons on the forums (like Mari’s/Zzzzz...’s Slow Finnish Lessons.)