According to the different vowels, the pronunciation of words can be divided into four categories: open call, straight call, closed call and pinch call, which are collectively called four calls, with differences at the beginning.

A vowel with an I or a vowel beginning with an I is called a sharp sound. In modern Chinese Pinyin, there are nine vowels that belong to the same sound, namely I, ia, ie, iao, iou, ian, in, ANG and ing.

The vowel is u or the one that starts with u is called "mouth to mouth". In modern Chinese Pinyin, there are 10 disyllabic vowels, namely: u, ua, uo, uai, uei, uan, uen, uang, ueng and ong.

Vowel ≤ or starts with ≤ In modern Chinese, there are five vowels, namely, u, u e, u an, u n and long.

The vowels are not I, U, U, or they can start with I, U, U. There are 15 vowels in modern Chinese Pinyin, which are -i (before and after), a, o, e, Mi, er, ai, ei, ao, ou, an, en, ang and eng.

Introduction to Putonghua:

Standard Mandarin/Mandarin? Another name of modern standard Chinese, pronounced with Beijing accent as the standard? Based on the northern mandarin dialect, the modern vernacular is used as the grammatical norm model of the common language.

Chinese is different from Putonghua. The promotion of Putonghua is not to eliminate dialects artificially, but to eliminate dialect barriers and facilitate social communication? There is no contradiction with the people's use of inherited dialects.