一、什么叫同位语
当两个指同一人或事物的句子成分放在同等位置时，若其中一个句子成分是用于说明或解释另一个句子成分的，那么用于起说明或解释作用的句子成分就叫做另一成分的同位语。如：
Laura Myers, a BBC reporter, asked for an interview. 劳拉迈尔，BBC的记者，要求采访。
Influenza, a common disease, has no cure. 流行性感冒是一种常见病，无特效药。
Mary, one of the most intelligent girls I know, is planning to attend the university. 玛丽是我所认识的最聪敏的姑娘之一，她正准备上大学。
Who is that man, the first in the front row? 前排第一个人是谁?
We have two children, a boy and a girl. 我们有两个孩子，一个男孩和一个女孩。
以上所举的同位语例子都是同位语的基本形式，一般不会出错。但有有几种同位语，或由于身本结构特殊，或由于它修饰的成分结构比较特殊，往往会引起误解。现小结并举例说明如下，希望引起同学们的注意。
二、特殊同位语归纳
1. 代词we, us, you等后接同位语
Are you two reading? 你们二人在看书吗?
They three joined the school team. 他们3人参加了校队。
She has great concern for us students. 她对我们学生很关心。
He asked you boys to be quiet. 他要你们男孩子安静些。
We girls often go to the movies together. 我们女孩子经常一起去看电影。
2. 不定式用作同位语
Soon came the order to start the general attack. 很快下达了发起总攻的命令。(to start the general attack与the order同位)
He followed the instruction to walk along a certain street where I picked him up. 他照吩咐沿某一条街走，我在那里接他上了车。(to walk along与the instruction同位)
3. -ing分词用作同位语
Hes getting a job tonight driving a truck. 他今晚得到一个开卡车的差事。(driving a track与a job同位)
She got a place in a laundry ironing shirts. 她在一家洗衣店得到一个熨衣服的职位。(ironing shirts与a place同位)
The first plan, attacking at night, was turned down. 第一个计划是夜袭，被拒绝了。(attacking at night与the first plan同位)
4. 形容词用作同位语
The current affair, the biggest in its history, is being held in Guangzhou. 目前的交易会，是有史以来规模最大的，正在广州举行。
He read all kinds of books, ancient and modern, Chinese and foreign. 他读了很多书，古今中外都有。
People, old and young, took to the streets to watch the parade. 老老少少的人都来到街头观看游行。
【注】这类同位语与定语比较接近，可转换成定语从句。如：
The current affair, the biggest in its history, is being held in Guangzhou.
=The current affair, which is the biggest in its history, is being held in Guangzhou.