Pinyin: y ǔ z ǐ há ng y √.

Spelling: Pronunciation is very important in the process of spelling, and the correct tone is the foundation.

Tone refers to the changes of syllables such as high, low, rising, falling, bending, straight, long and short.

Mandarin has four tones, namely, flat tone, rising tone, rising tone and falling tone. The four symbols "-,/,∨," are used as key signatures.