Hakkas migrated from the Central Plains to the South.

Now, surrounded by Putonghua, Shanxi still retains the Jin dialect.

Xuzhou is the Jianghuai Mandarin, which is the transition between Mandarin and Wu dialect. There are some characteristics of Wu dialect, such as entering tone. Wu dialect has a history of three thousand years.

Korean is also greatly influenced by ancient Chinese.

In the final analysis, all of them are similar because they retain the characteristics of ancient Chinese.

Northern Mandarin is the basis of Putonghua, which is relatively new and far from ancient Chinese.