Kanji
Kanji (漢字) are Chinese-derived characters used to write some elements of the Japanese language. Kanji are not used in exactly the same way as traditional or simplified Chinese characters used to write modern Mandarin or other varieties of Chinese,[1] though many characters do have similar or the same meanings. This means that, to some degree, literate readers of Chinese or Japanese can recognise meanings in the other language, though this depends very much on the complexity of the text.
Kanji have a long history in Japan, emerging perhaps by the fifth century AD, but initially their use was restricted to the work of highly literate elites who brought the characters from China, often via Korea. Other writing systems with symbols based on simplified kanji also later emerged, and widespread use of kanji therefore occurred relatively late in Japanese history. Today, there are 1,945 'official' kanji (常用漢字 jooyoo kanji) sanctioned by the Japanese government for learning in schools, and another 983 official characters mainly used in people's names (人名用漢字 jinmeeyoo kanji), but there are also many others that are outside this list.
Early kanji were borrowed alongside large numbers of Chinese words, so most kanji have at least two 'readings' (ways to pronounce the character). One is derived from the Chinese lexicon (音読み on'yomi) - often from up to about 1,500 years ago, and filtered through Japanese phonology - while the other is a native Japanese reading (訓読み kun'yomi). As Chinese and Japanese are unrelated in syntactic, phonological and other grammatical terms, these two readings are very different. For example, the character 口 'mouth' can be read as KOO[2] in the Chinese reading and as kuchi in the Japanese reading. Often, the Chinese reading is used in compounds such as 人口 (jinkoo 'population') while the Japanese form is used when the character stands alone. Chinese readings are common for nouns as well, while verbs often use the Japanese reading: for example, 寝 in 就寝する shuushin suru 'retiring [to bed]' uses the Chinese reading SHIN in the noun shuushin but in the more common verb 寝る neru 'to lie down [go to sleep]', the Japanese reading ne occurs.
Japanese also makes use of fewer characters than Chinese, so many characters have multiple readings. In modern Japanese, new words borrowed from other languages are not written in kanji but phonologically in カタカナ katakana, a script which represents the moras of Japanese (units similar to syllables). Other words, particularly grammatical particles, are written in another mora-based script, ひらがな hiragana. In the past, these scripts were more widely used, and so today there are many words in Japanese that have no kanji assigned to them, or for which the characters are little-used: 熊 kuma 'bear' is more often written in hiragana or katakana as くま or クマ, for example.