Once you start to learn Chinese you’ll soon come across chengyu 成语 or Chinese idioms. These are mainly four-character phrases that in most cases derive from ancient Chinese literature such as myths, legends, and historical stories. They are similar in some ways to Western proverbs, the ones that have their roots in Aesop’s fables or stories from Greek mythology. There are literally thousands of these Chinese idioms (30,000 according to one count), although many are no longer widely used. They are most commonly found in Chinese writing, although many also crop up in Chinese conversation.