Furthermore, there is no clear definition of what constitutes a language: for instance some languages share writing systems but are spoken differently, while others are identical when spoken but are written using different alphabets. For example, different "dialects" of Chinese use the same characters with the same meanings, but these can be pronounced very differently in different varieties. Japanese also uses large numbers of Kanji characters (of Chinese origin) to mean the same as in Chinese, but they often have different "readings" (yomi) some of which may be pronounced as in Chinese while others are totally different.