There are eight sentences in each section, and every two sentences form a couplet, which is divided into four parts.

Metric poems are generally eight sentences each, and more than eight sentences are called parallel sentences or long sentences. An eight-sentence metrical poem, every two sentences are linked together, is called quadruple. Traditionally, the first couplet is the first couplet, the second couplet is the parallel couplet, the third couplet is the neck couplet, and the fourth couplet is the tail couplet. The upper sentence of each couplet is called a sentence, the lower sentence is called a sentence, and the two sentences form a sentence relationship; The relationship between prepositional antithesis sentence and prepositional sentence is called adjacent sentence relationship.

The number of words in a metrical poem is uniform, and each sentence is five or seven words, which are called five-word metrical poem and seven-word metrical poem respectively. The five laws stipulate that every sentence has five words, and the first word is forty words; Seven laws stipulate seven words for each sentence and fifty-six words for the whole sentence. There are also six-character sentences, all of which begin with 48 characters. They are called six-character poems, and there are few handed down works.

Rhyme is a genre of China's traditional poetry, which belongs to the category of modern poetry. Named for its strict metrical requirements. Metric poems originated from Shen Yue and other new-style poems that emphasized the antithesis of metrical poems in the Southern Dynasties, and were further developed and stereotyped by Shen Quanqi and Song in the early Tang Dynasty, and prevailed in the Tang and Song Dynasties. Rhyme has strict rules in word, rhyme, even tone and antithesis. Its common types are five-character poems and seven-character poems.