The last character of the first line (oblique tone) is pasted on the right (upper hand), and the last character (flat tone) of the second line is pasted on the left (lower hand). Based on this, it is judged that "the door is filled with joy and success every year" should be on the right. Here is an introduction to couplets:
1. Origin
Couplets are also called couplets, door pairs, spring stickers, spring couplets, antithetical couplets, peach charms, and couplets (because they were often hung in halls in ancient times). It is named after the pillars of the house hall), etc., is a kind of dual literature, and one theory is that it originated from Taofu.
Another source is the spring couplets. The ancients often posted the word "Yichun" on the first day of spring. Later, they gradually developed into spring couplets, which express the Chinese working people's good wishes to ward off evil spirits, eliminate disasters, and welcome good fortune. Couplets are dual sentences written on paper, cloth or carved on bamboo, wood, or pillars. Simple words but profound meanings, neat contrasts, coordinated oblique and oblique lines, the same number of words, and the same structure are the unique art forms of the Chinese language.
2. Form
As the name suggests, couplets must be in "pairs", that is, they are composed of an upper couplet and a lower couplet. The number of words in the upper and lower couplets must be equal, and the content must be consistent, that is, the upper and lower couplets must be "connected" (opposed to each other). Two unrelated sentences cannot be combined casually to form a couplet.
Couplets are generally written vertically, with the last character (oblique tone) of the first couplet on the right (upper hand) and the last character (flat tone) of the second couplet on the left (lower hand).
Although the antithesis of couplets is similar to that of poetry, it is more demanding than poetry. There are broad and narrow couplets. A wide pair only requires that the contents of the upper and lower couplets are connected to form a couplet, while a narrow pair must be written strictly according to the standards of "Li Weng Duiyun". However, in practical couplets, wide pairs are more commonly used, while narrow pairs are rarely used because the requirements for antithesis are too strict.
The rules of level and obliqueness of couplets are basically the same as those of poetry. Generally, the basic rules of rhythmic poetry are applied.
In addition to distinguishing the upper and lower couplets from the content of the couplets, it is more important to judge from the oblique sounds at the end of the couplets. The couplets strictly stipulate that the last word of the first couplet should be in oblique tone, and the last word of the second couplet should be in flat tone. Later generations called this rule the ups and downs.
It must be noted that the "four tones" of ancient Chinese and modern Chinese are somewhat different. Since the promotion of Hanyu pinyin and the adoption of Beijing pronunciation as the national common language, the same Chinese characters have changed.
Taboos on couplets
A couplet must match words with different meanings in order to be considered qualified. When making couplets, some people mistakenly believe that "parts of speech are relative" and think that the upper and lower couplets have the same meaning, which is the reason for the correct syntax. In fact, this is the mistake of closing the palms together. No matter how long or short a couplet is, the number of words is always limited. If you repeat one thing in a limited space, what’s the point? Therefore, joining the palms together is the first taboo in couplets.
Reference for the above content: Baidu Encyclopedia-Couplet