The upper part and the lower part must have the same number of words and neat form. Generally, the five-character couplet and seven-character couplet are the most frequently used.
Second, the parts of speech are the same. The parts of speech of words in couplets opposite to the upper couplet and the lower couplet should be the same-content words to content words, function words to function words. Such as: the sea is wide and the fish jumps; The sky is high and birds can fly.
In couplets, "sea" and "sky" are nouns, "breadth" and "height" are adjectives, "goods" and "people" are prepositions, "fish" and "bird" are nouns, and "yue" and "fly" are verbs.
Third: Syntactic similarity. The upper and lower couplets should correspond in structure-juxtaposition to juxtaposition, subject-predicate to subject-predicate, verb-object to verb-object, partiality to partiality, etc. Such as: home and Pepsi Shun; Peace and prosperity.
Family harmony and Guotai in the upper and lower couplet are subject-predicate structures, and Baishishun and Wan Min 'an are also subject-predicate structures.
Fourth: rhythm correspondence. The rhythm of the upper and lower couplets must be consistent, and the rhythm must be symmetrical, monosyllabic to monosyllabic, disyllabic to disyllabic, and polysyllabic to polysyllabic. Such as: spring enters-spring gate-spring is not old; Fu Lin-blessed land-infinite happiness.
Fifth: Content-related. Apart from "no love", the contents of the first part and the second part are related, closely surrounding the theme. Such as: Matsuzaka, Plum, Sanyou; Peach, plum and apricot are warm in spring.
The contents of this couplet complement each other.
Sixth: the integration of levels and levels. Flat, that is, flat and flat of Chinese characters. The tones of ancient Chinese are divided into four tones: flat, rising, going and entering. Couplets pay attention to flatness, flatness, rightness and harmony, which refers to the two opposite words of upper and lower couplets. They can't all be flat or flat, but they should be flat, so they look patchy, catchy and pleasant, which constitutes the musical beauty of the language. Among them, couplets pay attention to flat and even, with the strictest ending. The pronunciation of the last word of the upper couplet must be flat, and the pronunciation of the last word of the lower couplet must be flat. Such as: days increase years, people increase life; Dry kungfu is everywhere in spring.
However, due to the flexibility of the number of words, the length of sentences, the structure and rhythm of couplets, if we don't distinguish their specific situations, we may not be able to sit in the right place if we apply metrical poems to the flat lines of any Spring Festival couplets or other couplets. It should be noted that couplets are literati literature, folk literature and refined and popular literature. For folk lovers of couplets, it is inappropriate to overemphasize the rhyme of couplets. It is best to distinguish between situations, temper justice with mercy, and it varies from person to person. Not to mention folk people, it is the celebrities who write couplets. "If there are strange sentences, the truth is not equal" and "Don't hurt people with words" (what Lin Daiyu said to Xiangling when she talked about poetry in a Dream of Red Mansions). However, this does not mean that we can ignore the rules of couplets. "There are differences between leniency and severity, which vary from person to person" is based on the premise of "combining leniency and severity". After all, "antithesis" is the biggest feature of couplets and the bottom line of couplet rules. This bottom line should not be discarded, it should be kept!