1、作定语。作定语的分词通常放在被修饰的名词之前。如果被修饰的词是something，anything，everything，nothing等，则分词放在这些词之后。分词短语通常放在被修饰的名词之后。
例如：
This is an interesting book. (=This is a book. It is interesting. )这是一本有趣的书。
There is something interesting in the news. (=There is something in the news. It is interesting.)消息中有些有趣的事。
The man sitting by the window is our math teacher. (=The man who is sitting by the window is our math teacher.)靠窗户坐着的那个人是我们的数学老师。
The machine run by the old worker is made in Shanghai. (=The machine that is run by the old worker is made in Shanghai.)那位老工人开的机器是上海造的。
Most of students singing were girls. (=Most of the students who were singing…) 唱歌的学生多数是女生。
Many of the villagers questioned refused to answer. (=Many of the villagers who were questioned…) 被问的许多村里人都拒绝。
注意：(1)分词作定语与动名词作定语的区别：分词和它所修饰的名词有逻辑上的主、谓关系。
动名词则没有这种关系，而表示它所修饰的词的用途或有关动作。
(2)现在分词作定语时，它表示动作正在进行或与谓语动词所表示的动作同时发生(或差不多同时发生)。
(3)be的现在分词being不能用作定语(可用作状语或被动语态中的助动词)。
表示这种概念时，也用主从复合句结构。
2、作状语。分词和分词短语作状语时，可以表示时间、原因、行为方式等意义。表示时间和原因的分词短语相当于对应的状语从句。
例如：
Seeing the teacher entering the room, the students stood up. (=When the students saw the teacher entering the room. They stood up.)学生们看见老师走进房间，都站了起来。
(时间)
Heated，the Metal expands. (=The metal expands if /when it is heated.)金属受热而膨胀。(条件、时间)
Being excited, I couldn’t go to sleep.(=As I was excited, I couldn’t go to sleep.)我兴奋得睡不着觉。(原因)
Being a student, he was interested in sports. (=As he was a student, he was interested in sports.)他是个学生，所以对体育运动感兴趣。(原因)
Inspired by Dr.Yang’s speech, Li Hua and his classmates decided to study physics harder. (=As they were inspired by Dr.Yang’s speech, Li Hua and his classmates decided to study physics harder。
)李华和他的同学们受到杨博士讲话的鼓舞，决定更加努力学习物理。
(原因)
The children went away laughing. (=The children went away.They laughed as they went.) 孩子们笑着走开了。(行为方式)
The professor stood there, surrounded by many students. (=The professor stood there. He was surrounded by many students.) 教授站在那里，许多学生围着他。(行为方式)
While reading the newspaper, father nodded from time to time. (=While he was reading the newspaper, father nodded from time to time.) 看报时，父亲不时地点头。
(时间)(分词前，可加表示时间的连词while或when。
)
3、作宾语补足语。
例如：
Can you get the machine going again? 你能使机器再动起来吗?
You should have your hair cut. 你该理发了。
I saw him coming last night. 我昨天晚上看见他来了。
4、作表语。
例如：
The film is very moving. 这部影片很感人。
Your homework is well done. 你的作业做得好。
The visitors looked surprised. 参观者看上去很惊讶。
The boys were seen walking on the grass. 有人看见孩子们在草地上散步。
5、作句子独立成分(分词有自己的逻辑主语时，称为独立主格结构) 。
例如：
Flags flying, the army men marched in the streets. 旗帜飘扬，军队在街上行进。
All his ribs broken, he lay half dead. 他的肋骨全部折断，半死不活地躺着。
分词(短语)作状语时，其逻辑主语必须与句子的主语一致。如果不一致，必须用独立主格结构来表示，也就是在分词前面加上它的逻辑主语。
My wife had a long talk with Sally, explaining why she didn’t want the children to play together我妻子与莎莉谈了很长时间，解释她为什么不想让孩子们在一起玩。
(现在分词explaining是句子主语my wife做的动作，它们之间是主动关系)
Given more attention, the trees could have grown better. 如果对这些树多关心一些，它们本来会长得更好。(过去分词given表示的动作是句子主语the trees承受的动作，它们之间是被动关系)
We explored the caves, Peter acting as guide. 我们到那山洞探险，彼得做向导。 (独立主格)
The train having gone, we had to wait another day. 分词短语做状语时，前面可以加上连词或介词，但是分词短语和句子之间不能用并列连词(如but，and)，因为并列连词接的是两个并列成分，