Classical Chinese is the language in which the classics of Chinese literature were written, from c. the 5th century BCE. For millennia thereafter, the written Chinese used in these works was imitated and iterated upon by scholars in the Sinosphere in a form now called Literary Chinese, which was used for almost all formal writing in China until the early 20th century. Its use is roughly comparable to that of Latin across post-Roman Europe. While not static throughout its history, its evolution has traditionally been guided by a conservative impulse: many changes found in the varieties of Chinese that later emerged are not reflected in the literary form. Due to millennia of this linguistic evolution, Literary Chinese is not intelligible when spoken aloud or read for an individual only familiar with modern vernacular Chinese. Over time, Literary Chinese began to be used in Japan, Ryukyu, Korea, and Vietnam, where it was originally introduced as the prestige form of the only known writing system, before eventually being adapted to write the local languages, which belonged to completely different language families. Each of these countries have their own reading systems for Classical Chinese text, in addition to their own inventories of Chinese character forms. Classical Chinese has largely been replaced by written vernacular Chinese among Chinese speakers; similarly, speakers of non-Chinese languages have largely abandoned Classical Chinese in favor of their respective local vernaculars. Although varieties of Chinese have diverged in various directions from the Old Chinese words in the Classical lexicon, many cognates can be still be found. Source: Wikipedia (en)