分词既具有动词的一些特征，又具有形容和副词的句法功能。它分为现在分词和过去分词两类。现在分词和过去分词的主要差别在于现在分词有一般式和完成式，过去分词则只有一般式。现在分词表动作正在进行，表主动。过去分词及物动词表动作已经完成，表被动。过去分词不及物动词表动作已经完成，表主动。
过去分词的句法功能：
1、作定语
I like to read the novel written by Lu Xun.
The woman sitting beside the broken window was a friend of mine.
2、作表语
When I came into the room, I found the window was broken.
I'm interested in this book.
3、作宾语补足语
I'm going to have my bike repaired.
When I walked home, I saw the thief caught by the police.
4、作状语
Seen from the top of the mountain, the city looks small.
The teacher came into the classroom, followed by his students.
现在分词的句法功能。
1、作状语
Seeing from the top of the mountain, I found the city was beautiful.
Walking along the street, they suddenly saw him.
2、作宾语
I hate being spoken ill of.
He considered visiting Japan during the winter vocation.
3、作表语
Seeing is believing.
The book is interesting.
4、作宾语补足语
I noticed him crossing the street.
Mother caught him smoking in the kitchen.
5、作定语
Do you know the man writing a letter?
The worker running a machine is my brother.
分词使用中的几个问题
1、现在分词的完成式
Having cleaned the room, I went out.
2、现在分词的否定式
Not having received any letter, he felt a little worried.
3、现在分词与过去分词的不同
现在分词表示主动、正在，过去分词表示被动、完成
I found the man killed there.
I found the man standing there.
4、have结构
We have the car repaired.
We have repaired the car.
We have Tom repair the car.
We have Tom repairing the car the whole morning.
5、分词作表语
We were excited at the news.
The football game is exciting.
6、独立主格结构
It being a fine day, we went out to visit the park.
II.例题
例1、Time_______，I'll go on a picnic with you.
A. permit B. to permit C. permitted D. permitting
解析：该题答案为D。Time permitting…是独立主格结构，意为"如果时间允许的话…"
例2、_______ if he had any bad habit, she replied that he was a heavy smoker.
A. Ask B. To ask C. Asked D. Asking
解析：该题答案为C。主语she是被问。