The vowels are ai, ei, uo, uai, uei, ie, iao, iou, ao, ou, ia, ua, and ü E. The full name of a compound vowel is a compound vowel, with thirteen vowels. A compound vowel refers to a vowel formed by combining two or three vowels, which should be regarded as a complete phonetic whole and cannot be interrupted when pronouncing.

Classification of compound vowels

Compound vowels can be divided into pre-sounding compound vowels, post-sounding compound vowels and middle-sounding compound vowels.

There are 13 vowels in Chinese Pinyin, which are divided into 9 binary vowels and 4 ternary vowels. The nine binary vowels are:

Ai, ei, ao, ou, ia, ie, ua, uo and üe, and the four triplet vowels are: iao, iou, uai and uei. Binary vowels can be divided into two types: pre-voiced vowels and post-voiced vowels, and triplet vowels are middle-voiced vowels.

When the vowel is pronounced before the vowel, the oral muscles relax and the vowels A, O and E are pronounced.

It is pronounced clearly and loudly, with a slightly longer sound value. The I and u(o) at the back are rhyme endings, and it is pronounced light, short and fuzzy, which only indicates the direction of tongue sliding.

When pronouncing the vowel of the compound vowel, the first vowel I, U and U is the rhyme head, which is read lightly, short and nervously, and the last vowel is the rhyme belly, which is read clearly, loudly and for a long time. Two vowels must be read as a whole.

When pronouncing the vowel of middle-ring compound vowel, the rhyme head is light and short, the rhyme end is vague, the sound value is not fixed, the rhyme belly is clear and loud, and the sound value is long. Before the pre-voiced binary vowel, add the lingual movements of I and U, and the original pre-voiced vowel will remain, thus forming the middle-voiced compound vowel.