Most couplets are popular in five words and seven languages, which is closely related to the ancient poetry "five words" and "seven laws" Other couplets have six characters, eight characters and nine characters. In addition to the above examples, five-character couplets such as "Woye Li Qianlu, Wan Qingshan Muchun" and "Spring in the ancient city, China is full of sunshine"; Six-character couplets such as "Dapeng Gao Xiang Wan Li, Xiaolong soaring for thousands of years" (year of the snake Spring Festival couplets), "Golden Rooster Wings Dance, Silver Dog Singing" (Spring Festival couplets in the Year of the Dog); Eight-character couplets, such as "Six Livestock Flourish, All Families Enjoy the Happiness, All Grains Prosper, Everything Renews" and "Farewell the Old Good News and Welcome the Spring Breeze to Blow All Families"; Nine-character couplets are like "Spring breeze turns rain into green Jiang Nanan, and snow reflects the sun and shines again in Hero City". In addition, there are more refined and wonderful four-character Spring Festival couplets, such as "New Year's Eve is gone, the Spring Festival is coming", "Spring returns to the earth, making China strong" and "peaches and plums are all over the world, and a generation is romantic". Because the format of Spring Festival couplets originated from China's classical poems, the original Spring Festival couplets required strict words to be even, that is, every word of the upper and lower couplets should be in one tone, and then the coherent skills should be used.
However, with the popularization of vernacular Chinese and popular culture, people have paid less attention to the strict antithesis principle pursued by the ancients, but a decent couplet should at least pay attention to equivalence in word selection, that is, the number of words and the part of speech should be relative. According to the norms of modern Chinese, nouns, adjectives, verbs, numerals and other phrases in the upper and lower couplets should be arranged in an orderly way, and the last word of each pair of upper and lower couplets should be at least even. Generally speaking, if the last word in the upper couplet is a hyphen (that is, the third and fourth sounds of Chinese Pinyin), then the last word in the lower couplet should be a flat tone (that is, the first and second sounds of Chinese Pinyin). This should be the minimum requirement for creating couplets, otherwise it is not called couplets, at least it is not a standard couplet.