History of education
Although there are more than 40,000 Chinese characters in written Chinese, many are rarely used. Studies have shown that full literacy in the Chinese language requires a knowledge of only between three and four thousand characters.
Written Chinese
Various current Chinese characters have been traced back to the late Shang Dynasty about 1200–1050 BC, but the process of creating characters is thought to have begun some centuries earlier. After a period of variation and evolution, Chinese characters were standardized under the Qin Dynasty (221–206 BC). Over the millennia, these characters have evolved into well-developed styles of Chinese calligraphy. As the varieties of Chinese diverged, a situation of diglossia developed, with speakers of mutually unintelligible varieties able to communicate through writing using Classical Chinese. In the early 20th century, Classical Chinese was replaced in this role by written vernacular Chinese, corresponding to the standard spoken language ("Mandarin"). Although most other varieties of Chinese are not written, there are traditions of written Cantonese, written Shanghainese and written Hokkien, among others.