Original sentence: As of 1991, there are at least 77 million speakers of Wu Chinese, making it the second most populous Chinese language after Mandarin, which has 800 million speakers, and the 10th most populous language in the world
Edited sentence: As of 1991, there are at least 77 million speakers of Wu Chinese.Cantonese is the second most populous Chinese language after Mandarin, which has 800 million speakers, and it is the 16th most populous language in the world.However Wu is not a single language, and  is divided into many mutally unintelligible dialects