4．用在序数词和形容词最高级前,以及在方位词前。如：

　 The Nile is the longest river in the world.

　 He won the first prize.

The sun rises in the east.

3．指前面提到过的人或事物，如：

　 Here is a picture of a modern car factory. My father works in the factory.

2．特指某(些)人或某(些)事物，如： 　　　 The girl in red is my sister.

　 The man over there is our English teacher.

　 The book on the desk is mine.

1．指彼此都知道的人或事物，如： 　　　 Open the door, please. 　　　 Go and close the window.

5．用于某些固定词组中，如：

　 a few, a little, a lot of, a number of, just a minute, in a hurry, for a while, for a long time, a cup of, a bottle of, have a rest, have a talk, have a fever, have a good time, have(take) a walk,　 have a toothache, take a bath, give a lesson

(二)定冠词

定冠词的用法如下：

4．表示数量，有“一”的意思，如：

　 Behind the house there is a garden.

　 once a week.

3．泛指某人或某物，但未具体说明何人、何物，如：

　 A boy is waiting for me.

Give me a pen, please.

2．说明某人或某东西属于哪一类，如：

　This is a book.

　He used to be an engineer.

1．用在单数可数名词前，表示一类人或事物，如：

A dictionary is a useful book.

An underground train can start and stop quickly.

3．如果不定冠词和名词之间有其他词，不定冠词的形式仍取决于它后面第一个词的语音形式。例如a rich uncle , a beautiful actress。

不定冠词的用法如下：