l)特指某人或某物。The book on the desk is mine.
2)指双方都知道的人或事物。Where are the new books,Jim?
3)指上文提到过的人或物。There is an old woman. The old woman is my grandma.
4)用在世上独一无二的事物名词前。the sun, the sky
5)用在序数词和形容词最高级前。The third one
6)用在山脉、江河、海洋、岛等名词前。the Yellow River
7)用在姓氏复数形式之前,表示“某某一家”或“某某夫妇”。the Greens
9)用在由普通名词构成的专有名词前。the Great Wall
10)用在某些习惯用语中。in the morning