I'm a professor of Korean and Chinese. Most foreign learners I've seen are terrible at pronunciation. What are people doing?

Most learners of Korean and Chinese either have a native accent or they sound like it's their first day speaking. This is unique in my experience to these two languages. I've also seen this in Japanese. Most other languages, people have a foreign accent but they are completely understandable and can replicate most sounds. This isn't true for Korean, Chinese, or Japanese. I've considered the possibility that it's because English doesn't have a tonal system, but other non-tonal languages (Vietnamese, Bahasa Indonesia, Thai) are learned much more easily. <br><br>I have to have native speakers repeat themselves all the time when they try to speak to me in English. So it's not a matter of intelligence. I think this has to do with the sounds and structure of Asian languages. Korean has a completely different grammar system that no European or Middle Eastern language possesses. Chinese has a tonal system and completely different sounds (zh, q, x) that are absent from even the Asian languages I listed. Japanese has a combination of completely different sounds (n, ts, sh) plus an entirely different grammar system. I think this is why so many learners are completely unable to speak these languages fluently. <br><br>Frustrating because I constantly see people saying "anyone can learn any language". I've seen tons of students go from completely illiterate to being able to have conversations in Russian, Arabic, German, Spanish, Portuguese, Italian, and French. But Asian languages are just completely different and the depth of knowledge you need to learn is completely different. I'm not saying people can't learn them, but I think people underestimate how much time it takes to get to fluency.