Second, the nasal sounds before and after cannot be distinguished.

Third, the pronunciation of the third sound is not accurate.

Fourth, the rule of tone sandhi does not conform to the habit of Putonghua.

Fifth, the incorrect use of Er Hua is mainly manifested in the fact that southerners don't use Er Hua, while some northerners abuse Er Hua.

Sixth, we can't use light tone correctly.

Seven, F and H are confused, mainly from southerners.

Eight, some words with middle sound W in Mandarin are pronounced as V.

Nine, send some unventilated sounds into voiced sounds that are not found in Mandarin.