This is what we call "upper two/lower three", in which "lower three" can be divided into "upper one/lower two" or "upper two/lower one".
The general rule of seven-character quatrains is "thinking up/down three", in which thinking up can be divided into two/down two, and the down three can be divided into two/down two or up two/down two.
Extended data
Poetic meter
Seven-character quatrains belong to modern poems with strict metrical requirements. The first is fixed length. The whole poem consists of four sentences, each with seven words, totaling * * * 28 words. Secondly, the rhyme is rigorous, usually only flat, not rhyming. Also pay attention to the level tone, that is, it conforms to the level tone law, that is, under normal circumstances, two syllables (two words) are a step, and the level tone is alternately arranged.
According to the level of the first two words in the first sentence, seven-character quatrains can be divided into two categories: upgrading and upgrading. Among them, there are two types of flat-rising: one is flat-rising and flat-receiving, and the first sentence rhymes; Second, the first sentence doesn't rhyme.
There are also two types of pouting: one is to flatten out and rhyme the first sentence; Second, from beginning to end, the first sentence doesn't rhyme.
According to Pinglv, seven-character quatrains have four standard sentence patterns:
First, flat and flat (flat and flat, the last word is flat, called flat feet);
The second is flat and flat (flat and flat, the last word is flat and flat, called flat and flat feet);
The third is flat and flat (flat and flat, the last word is flat, called flat feet);
Fourth, plain (plain, the last word is plain, so it is called plain). Its flat sticker has a certain elasticity, that is, the so-called "135 regardless, 246 is clear", but it is also necessary to avoid making a flat three-level tone.
Baidu encyclopedia-seven-character quatrains