Guizhou dialect, Chongqing dialect and Sichuan dialect, but this is limited to the pronunciation of Putonghua in the provincial capitals. Cantonese is not so close, but there are similarities. The language, pronunciation and intonation in these places are basically similar. You can travel all over southwest Yunnan, Guizhou, Sichuan, Chongqing, Xiangxi and many other places without being blacked out. The following are the reasons why southwest dialect is close to northern dialect:

Mandarin is the earliest name of the official standard language. In 1909, Mandarin is called "Mandarin", while in 1956, the word "Mandarin" is used to refer to "Mandarin dialect".

Mandarin dialects can be divided into eight sub-dialects: Beijing Mandarin, Central Plains Mandarin, northeastern mandarin, Jilu Mandarin, Jiaoliao Mandarin, Lanyin Mandarin, Southwest Mandarin and Jianghuai Mandarin.

We can learn one thing from the DNA roadmap of human migration. Before Shang and Zhou Dynasties, the yellow race trudged north along the Yunnan-Guizhou Plateau and finally reached the ancient Central Plains. They are called Qian Qiang, the same ancestor of China and Tibet: China people. Chinese eventually became the main population of China and the main source of Han nationality.

Therefore, the northern dialect used by China people has become the most widely used language in China. However, the Southwest Mandarin is located on the route of thousands of kilometers that China people moved northward in those years, which is the human cultural and genetic basis for Southwest Mandarin to keep basically the same pronunciation and intonation from Yunnan to Guizhou and from north to south for thousands of kilometers. This is why Southwest Mandarin is the closest language to Northern Mandarin.