非谓语动词在句子中充当除谓语以外的句子成分的动词形式叫做非谓语动词。非谓语动词分为三种形式:不定式，动名词，和分词(分词包括现在分词和过去分词)。
1）不定式　　　 to do
2）动名词　　　 doing
3）分词　　　　　 doing/done
下面的动词常常接to do做宾语
agree; ask; afford; attempt; choose;
decide; determine;demand; expect;
hope; learn; manage; offer; pretend;
promise; remain;refuse; want; wish
下面的动词常常接doing 做宾语
advise; admit; avoid(避免); appreciate;
can’t help; consider; delay; deny(否认);
enjoy; escape; excuse; finish;forgive;
fancy(想不到); imagine; keep; mind;
miss; put off; postpone; pardon;
　　　practise; suggest; understand;
下面的v.常常接to do 做宾补，
类似 tell sb. to do sth.
ask; advise; allow; beg; cause;　enable; expect; forbid; force; invite; inspire; mean; order; persuade; permit; promise(主补); require; set;　teach; tell; want; warn
下面的v.常常接doing/done 做宾补，
keep; find; see; watch; feel; leave; catch; stop; prevent;get; have注意事项：
1 主语：to do sth. 将来；一次；具体
doing sth. 一般；一贯；抽象
e.g. Teaching is my job.
To go to college is his dream.
**一般用it做形式主语放在句首，不定式
做逻辑主语。在It is no good/no use/
后面，一般用动名词做主语。
e.g. It’s dangerous to swim in this river.
It’s no good crying over spilt milk.
It’s important to learn English grammar.
2宾语：注意下面的动词接 to do 和 doing 所
表达的不同含义。
*forget to do: 没有做 remember　doing: 做过
* try to do:　　试图做；努力做
try　doing:　试着做；试一试
* mean to do: 意图；有意做mean doing: 意味着
* stop to do: 停下来去做（另一件事）stop doing: 停止做
go on to do：继续做（另一件事）go on doing: 继续做（同一件事）　　　　　　
* regret doing: 后悔； 惋惜
regret to say/ to tell you: 遗憾地说/告诉
e3.下列带to 的短语,是介词，后面要求跟sth. /doing sth.
stick to坚持 turn to求助于 be used to习惯于
see to照料；处理be reduced to沦为；降为
object to反对be opposed to反对lead to导致
contribute to导致；做贡献get down to着手做devote oneself to献身于look forward to盼望pay attention to注意in addition to除了，还有时态变化
to do　将来/一般+主动
to be doing进行主动to have done完成+主动to be done将来/一般+被动to have been done完成+被动to have been doing完成+主动+进行
Example:
1.Her greatest wish is　　　　　　　　　　　　(读大学).
2.The boy pretended　___________　　(睡觉） when his mother came in.
3. Japan is reported _______________(袭击) by another earthquake.
4. The buildings burnt down in the fire remain ____________(重建).
5.Dr.Baker seems _______________a lot (旅游)around China.
to go to college　to be sleeping　to have been struckto be rebuilt　to have traveled2) 动名词的变化如下doing　主动　being done被动　having done完成
having been done完成+被动
3）分词的时态变化：done完成+被动（定语，补语，状语）doing进行+主动
having done完成+主动being done进行+被动having been done完成+被动（状语）改　　错1. It took her two hours finishing her homework.
It took her two hours to finish her homework.
2. Can you imagine Peter to sail across the Atlantic Ocean all by himself?　Peter sailing3. Go on doing the other exercise after you have finished this one. Go on to do5. I’d like to have this package to be weighed, Madam. Package　weighed　　　　　　　　　　　
系动词亦称联系动词（Link Verb），作为系动词，它本身有词义，但不能单独用作谓语，后边必须跟表语（亦称补语），构成系表结构说明主语的状况、性质、特征等情况。

说明：
有些系动词又是实义动词，该动词表达实义时，有词义，可单独作谓语，例如：
He fell ill yesterday.
他昨天病了。（fell是系动词，后跟补足语，说明主语情况。）
He fell off the ladder.
他从梯子上摔下来。fell是实义动词，单独作谓语。

1）状态系动词　　　 用来表示主语状态，只有be一词，例如：
He is a teacher. 他是一名教师。（is与补足语一起说明主语的身份。）
2）持续系动词　　　 用来表示主语继续或保持一种状况或态度，主要有keep, rest, remain, stay, lie, stand, 例如：
He always kept silent at meeting. 他开会时总保持沉默。
This matter rests a mystery. 此事仍是一个谜。
3）表像系动词　　　用来表示"看起来像"这一概念，主要有seem, appear, look, 例如：
He looks tired. 他看起来很累。
He seems (to be) very sad. 他看起来很伤心。
4）感官系动词　　　　感官系动词主要有feel, smell, sound, taste, 例如：
This kind of cloth feels very soft.
这种布手感很软。
This flower smells very sweet.
这朵花闻起来很香。
5）变化系动词　　　　 这些系动词表示主语变成什么样，变化系动词主要有become, grow, turn, fall, get, go, come, run.
例如：
He became mad after that. 自那之后，他疯了。
She grew rich within a short time. 她没多长时间就富了。
6）终止系动词　　　　 表示主语已终止动作，主要有prove, turn out, 表达"证实"，"变成"之意，例如：
The rumor proved false. 这谣言证实有假。
The search proved difficult. 搜查证实很难。
His plan turned out a success. 他的计划终于成功了。（turn out表终止性结果