1. 同位语通常皆放在其说明的名词（代词）之后。

 1．名词或名词短语用作同位语。 

（1）We have two children, a boy and a girl.  

（2）We, the Chinese people, are determined to build China into a powerful country. 

（3）Our neighbor Jack is a well-known captain.

（4）St. Peter, one of the most famous forts in Europe, is often visited by young men in winter.

（5）She is saving money to travel to Rome, the capital of Italy.

（6）Hawthorne’s book, The Scarlet Letter,  has been taken as one of the most controversial love stories.

2．代词用作同位语。  

（1）They all wanted to see him.

（2）Let’s you and me go to work, Oliver. 

3．数词用作同位语。 

（1）Are you two ready?

（2）They two went, we three stayed behind.

4．不定式与动名词用作同位语。 

（1）Their latest proposal, to concentrate on primary education, has met with some opposition.

（2）The first plan, attacking at night, was turned down. 

5．Of 短语用作同位语  (of前面的名词是后面名词的上义词)

     the city of Rome 罗马城

the art of writing 写作艺术

     the vice of smoking 吸烟嗜好 

6．从句用同位语，即同位语从句 

（1）The news that we are having a holiday tomorrow is not true. 

（2）We are not investigating the question whether he is trustworthy. 

2. 同位语的特殊使用

1. 同位语可以用来表示举例

He is interested in sports, especially ball games.

All of them — namely, most of them — have the course.

Some vegetables — for instance, carrots and garlic — can help cure certain diseases.

2. 同位语有时相当于省略了关系代词和系动词的定语从句

Toni Morrison, who is the winner of Nobel Prize for literature in 1993, is an Afro-American authoress.

 Toni Morrison, the winner of Nobel Prize for literature in 1993, is an Afro-American authoress.

3. 同位语可以表示列举

All of my school work—physics, literature, sociology, and calculus—got washed away when my house was flooded.

The hill, the river, even the tree, the piece of rock, all seem to impact on me.