定义
英语中单个的动词（以v.表示）只能充当谓语，如果想让v. 充当主语，宾语，表语，同位语，状语，补语，独立成分，则需要改变v.的形式， 这些就是非谓语动词
- 不定式(to v.)
- 现在分词(v.-ing)
- 动名词(v.-ing）
- 过去分词(v.-ed)
| 分类\功能 | 作名词(主语，宾语) | 作形容词(定语，表语，补语） | 作副词(状语） | |
| to do | Y | Y | Y | To be or not to be-that is the question |
| doing | Y(动名词） | Y | Y |
Seeing is believing. He came running into the room |
| done | Y | Y | The prisoner came in, followed by a guard. |
一般规律：
1. 非谓语做定语时，常位于名词之后， n + to do/doing/done.
2. 非谓语做状语通常的形式： to do/doing/done, 句子。 或者： 句子, to do/doing/done.
When Mrs. Richards walked towards him, he fled, slamming the door behind him. (doing短语作伴随状语）
To understand the situation completely requires more thought than we excepted.
It is almost impossible to take your mind off the journey.(it 形式主语， to do...作真正主语）
The baby pulls the tablecloth off the table, smashing half your best crockery and cutting himself in the process.(doing伴随状语）
Those planning a trip to remote areas, or intending to live in countries where drinking water is not readily available, should know about the various possible methods for making water safe.(doing做后置定语）
Mr. Green stood up in defense of the 16-year-old boy, saying that he was not the one to blame.
(blame 主动表被动）
It remains to be seen whether Jim will be fit enough to play in the finals.
When comparing different cultures, we often pay attention only to the differences without noticing the many similarities.
判断方法： 先判断是否有主动，被动。 再判断是否为现在，过去，将来。
标签：do,doing,状语,done,谓语,动词,主语 From： https://www.cnblogs.com/hongten/p/16882652.html