1.表示特定的人或东西。

Give me the magazine。

Have you decided on the prices yet?

The book on the table is an English dictionary。

Beijing is the capital of China。

2.复述前文提到的人或东西。

Last week， I saw a flim. The film is about a love story between two middle-aged people。

The old man saw a house in the field. He went into the house and found a beautiful girl sitting there and singing。

3.用于形容词前面，代表一类人或东西。

the poor 穷人 the rich 富人 the wounded 受伤的人

the sick 生病的人 the beautiful 美丽的事物 the old 老年人

the young 年青人

4.用于表示世界上独一无二的东西的名词前面。

the moon， the sun， the earth

The moon moves aroud the earth。

We have friends all over the world。

Dont build castles in the air。

5.用于序数词、方位名词、形容词与副词的最高级前面，副词最高级前面的the 可以省略。

January is the first month of the year。

The sun rises in the east。

Japan lies to the east of China。

Beijing lies in the north of China。

Ireland lies on the Great Britain。

At the Childrens Palace， some children learn to play the piano， others learn to play the violin。

Last week we went to the theatre。

Among the three girls she speaks English the best。

“东、南、西、北”作副词时，前面不加冠词。

We are walking south。

形容词最高级前若有物主代词，就不加定冠词。

Monday is my busiest day。

6.用于姓氏的复数形式前，表示一家人或夫妇俩。

The Lius have moved to Guangzhou。

The Simths came to China for visit in 1996.

7.不可数名词前面通常不加定冠词，但若有限制性定语修饰，或表示特定部分、特定内容时，前面需加定冠词。

Drink some water。

Is the water in the well fit for drink?

What do you think of the music?

He cant take the advice his mother gives him。