CJK characters
Chinese is written almost exclusively in Chinese characters. It requires over 3,000 characters for general literacy, but up to 40,000 characters for reasonably complete coverage. Japanese uses fewer characters — general literacy in Japanese can be expected with 1,945 characters. The use of Chinese characters in Korea is becoming increasingly rare, although idiosyncratic use of Chinese characters in proper names requires knowledge (and therefore availability) of many more characters. However, even today, students in South Korea are taught 1,800 characters.
Chinese characters
In Old Chinese including Classical Chinese, most words were monosyllabic and there was a close correspondence between characters and words. In modern Chinese, the majority of Chinese words today consist of two or more characters. Rather, a character almost always corresponds to a single syllable that is also a morpheme.
However, there are a few exceptions to this general correspondence, including bisyllabic morphemes (written with two characters), bimorphemic syllables (written with two characters) and cases where a single character represents a polysyllabic word or phrase.