<P> Chinese characters (traditional Chinese: 漢字; simplified Chinese: 汉字; pinyin: hànzì; literally: "Han characters") are logograms developed for the writing of Chinese . They have been adapted to write a number of other Asian languages . They remain a key component of the Japanese writing system (where they are known as kanji) and are occasionally used in the writing of Korean (where they are known as Hanja). They were formerly used in Vietnamese (in a system known as chữ Nôm) and Zhuang (in a system known as Sawndip). Collectively, they are known as CJK characters . Vietnamese is sometimes also included, making the abbreviation CJKV . </P> <P> Chinese characters constitute the oldest continuously used system of writing in the world . By virtue of their widespread current use in East Asia, and historic use throughout the Sinosphere, Chinese characters are among the most widely adopted writing systems in the world by number of users . </P> <P> Chinese characters number in the tens of thousands, though most of them are minor graphic variants encountered only in historical texts . Studies in China have shown that functional literacy in written Chinese requires a knowledge of between three and four thousand characters . In Japan, 2,136 are taught through secondary school (the Jōyō kanji); hundreds more are in everyday use . Due to post-WWII simplifications of Kanji in Japan as well as the post-WWII simplifications of characters in China, the Chinese characters used in Japan today are distinct from those used in China in several respects . There are various national standard lists of characters, forms, and pronunciations . Simplified forms of certain characters are used in mainland China, Singapore, and Malaysia; the corresponding traditional characters are used in Taiwan, Hong Kong, Macau, and to a limited extent in South Korea . </P> <P> In Japan, common characters are written in post-WWII Japan - specific simplified forms (shinjitai), which are usually closer to traditional forms than Chinese simplifications are, while uncommon characters are written in Japanese traditional forms (kyūjitai), which are virtually identical to Chinese traditional forms . Interestingly enough, many Chinese simplified forms were copied from shinjitai forms . In South Korea, when Chinese characters are used, they are in traditional form, essentially identical to those used in Taiwan and Hong Kong where the official writing system is traditional Chinese . Teaching of Chinese characters in South Korea starts in the 7th grade and continues until the 12th grade; a total of 1,800 characters are taught, though these characters are used only in certain cases (on names, signs, academic papers, historical writings, etc .) and are slowly declining in use as native alphabetical hangul supplanted them in most aspects of Korean society . </P>

How many chinese letters are in the alphabet