I strongly recommend Hujiang Online School. I am a student studying Korean. Usually I go to Hujiang to find information. Where information is relatively complete, systematic and up-to-date, many of them are current languages. Ps: Language changes quickly. I haven't attended Hujiang's language class, but I have seen the introduction video, which is still good. You can watch any number of videos online, anytime, anywhere, without any restrictions, which is very convenient. Therefore, I am very supportive of Hujiang. I hope it helps you.