六书: The Six-Principles Theory of Chinese
              Character Formation

According to traditional analysis, Chinese characters have six etymological origins, called the 六书 (traditional characters: 六書), the 'Six Letters/Writings':

1) Pictograms
   ▪ stylized drawings of things they represent
▪ only about 600 characters total
▪ e.g. 日 'sun', 山 'mountain', 人 'person'
2) Simple Indicatives/Ideograms
   ▪ non-arbitrary sign for an abstract concept
▪ e.g. 一 'one',  二 'two', 上 'above', 下 'under'
3 Associative Compounds
   ▪ juxtaposition of two or more graphic
▪ e.g. 女 'woman' + 子 'child' = 好 'good'
4) Phono-semantic Compounds
   ▪ part meaning (radical), part phonetic
▪ over 90% of Chinese characters
▪ e.g. 口 'mouth' + 未 (phonetic) = 味 'flavor'
5) Borrowed Characters
   ▪ written form borrowed from homophonous 
▪ e.g. ancient 来 'wheat' sounded like 'to
     come', now 'to come' is written 来 (though,
     over the years, wheat has changed...)

6) Derived Characters
   ▪ least understood 六书 principle
▪ similar etymologies with slight alterations
▪ e.g. 老 'old' and 考 'a test'

Source: wikipedia.org (01.29.08)
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