The origins, stories, and meanings of chengyu, or Chinese idioms are closely related to China’s long history. Every chengyu is linked to historical facts, figures, and social customs. Many of them were derived from myths and fables. Myths reflect people’s understanding of the world and nature, and their yearning for a better society, while fables are stories that use animals and objects as characters to teach moral lessons. For example, hu jia hu wei (the fox borrows the tiger’s ferocity—to rely on connections to bully others) and yu bang xiang zheng (the fight between the snipe and the clam—two parties fighting amongst themselves will lose out to a third) are based on fables.
Chengyu often derive from classical works in which many interesting and instructional stories were recorded. Examples such as zhi shang tan bing (to discuss military matters on paper—to be an armchair general) and wo xin chang dan (to sleep on brushwood and taste gall—to patiently endure hardships in hopes of revenge) are both from the Shi ji (Records of the historian). Chinese culture is extremely rich with texts that have become classics over thousands of years. For instance, the Shi jing (Classic of songs), Lun yu (Analects), and Sunzi bingfa (The art of war) are all sources of chengyu. Many ancient texts contain concise and irrefutable statements about life, which are the best sources of chengyu, such as zhi ji zhi bi (know yourself, know your enemy) from Sunzi bingfa and bu chi xia wen (not ashamed to ask one’s subordinates) from the Lun yu.
Since many chengyu are from historical stories, legends, and old sayings, reading them literally would cause misunderstanding. Truly to understand a chengyu, it is important to study its context, its related story, and its change in meaning over time. For example, the literal meaning of si mian chu ge is “the songs of Chu are [heard] on all sides,” which refers to the famous battle at Gaixia (in modern Lingbi county, Anhui). At the end of the Qin dynasty (221–206 BCE), the leader of the Han forces, Liu Bang (256–195 BCE), defeated the leader of the Chu forces, Xiang Yu. When Xiang Yu (232–202 BCE) was trapped at Gaixia, his troops heard Chu songs sung from all directions and thought that Chu had fallen; the morale of his troops was greatly reduced. In fact, however, Liu Bang ordered his troops and the Chu prisoners to sing the songs to dishearten the Chu troops. This idiom is used to describe a difficult situation when someone is helplessly outnumbered. In addition, a great number of chengyu are from life and working experiences. They are vivid, humorous sayings with no profound story behind them. Therefore, they can be understood easily by reading them literally, such as tong bing xiang lian (fellow sufferers have mutual sympathy) and ku jin gan lai (when bitterness ends, sweetness comes).
The basic structure of a chengyu is a four-character phrase (some chengyu are formed with three, four, five, or more characters). Most of them are derived from texts and are modified so that the original grammatical structure and syntax become highly compact and synthetic. The four-character structure caters to a linguistic preference in Chinese for pairs. Additionally, they are both veiled and meaningful. For example, the Northern Dynasties (386–581) yuefu poem “Mulan ci” (Ballad of Mulan) has a line that reads “the male hare’s feet fuss about, the female hare’s eyes feign befuddlement; a couple of hares running along, how can you determine their sex?” This line is abbreviated to a four-character idiom pu shuo mi li (fuss and befuddlement). Another example is from the “Guo feng” (Airs of the states) in the Shi jing. The line “There he is plucking mugwort. / One day without seeing him is like three years” is compacted into yi ri san qiu (one day, three years).
The meanings of chengyu change over time, so to study their development properly one should not take the words too literally. For example, bu qiu shen jie (do not seek to understand thoroughly) is from Tao Yuanming’s (365?–427) “Biography of Mr. Five Willows.” The original text reads “[Mr. Five Willows] loves reading books, but does not seek to understand them thoroughly. When he feels empathy with what he reads, he is so happy that he forgets to eat.” Here, bu qiu shen jie means paying more attention to the essential meaning of the books, instead of reading them word-by-word. The meaning of this idiom is positive in the original text, but today, it means that one is not hard working and does not seek to gain a deep understanding; in short, it has become a negative description.
Chengyu are often metaphorical. For example, the phrase yu hou chun sun literally means “bamboo shoots after a spring rain.” Because the spring rain makes bamboo shoots grow fast, this idiom has become a metaphor indicating that something increases quickly or vigorously. The idiom shui luo shi chu (as the water recedes, the rocks appear) was originally a description of a landscape scene from the brush of Su Shi (1037–1101)—“the mountain is high, so the moon seems small; as the water recedes, the rocks appear.” But now it is a metaphor signifying that the truth will come to light.
Different from yanyu (proverbs), xiehouyu (enigmatic sayings), and guanyongyu (common idioms), chengyu are idioms mostly in the form of a four-character phrase and are often literary allusions expressed in literary language. Yanyu, on the other hand, can be of any length. Take for instance, hen tie bu cheng gang (to hate iron for not becoming steel—to be disappointed that someone does not meet expectations) and xin guan shang ren san ba huo (the new boss cracks the whip three times—a new broom sweeps clean). Xiehouyu are made up of two phrases. The first part is equivalent to a riddle while the second part supplies an answer. For example, “a clay Bodhisattva fording a river—cannot guarantee his own safety.” Guanyongyu are usually three-characters in length with a verb–object structure, such as kai ye che (literally “driving at night,” meaning “to burn the midnight oil”) and guan mi tang (literally “pouring rice soup,” meaning “to butter somebody up”)