动词 1. 不定式定义：由to＋动词原形构成。2.用途：主动形式被动形式。
一般式 （not) to make （not) to be made
[疑问词＋不定式结构]
疑问词who,what,which,when,where,whether,how后可接不定式构成不定式短语，在句中作主语、宾语、表语等。如：
①when to le**e for london has not been decided yet. （不定式在句子中做主语）
②mr. smith didn't know whether to le**e or stay there. （不定式在句子中做宾语）
③i asked professor xu how to learn english well. （不定式在句子中做间接宾语）
④the question was where to get the medicine needed. （不定式在句子中表语）
以上例句中疑问词＋不定式部分，均可转换为相应的从句形式。如：①when we shall le**e…③…how i could learn…
[动词不定式的语法功能]
一、作主语。
动词不定式作主语时，句子的谓语动词常用单数，其位置有以下两种：
(1)把不定式置于句首。如：
to get there by bike will take us half an hour.
(2)用it作形式主语，把真正的主语不定式置于句后，常用于下列句式中。如：
①it＋be＋名词＋to do
it's our duty to take good care of the old.
二、作宾语。
1) 动词+ 不定式
afford. aim. appear.
agree. arrange. ask.
be. decide. bother.
care. choose. come.
dare. demand. desire.
determine . expect. elect.
ende**or .hope. fail.
happen. help. hesitate .
learn . long. mean.
manage, offer. ought. plan .
prepare. pretend . promise.
refuse. seem. tend.
wait. wish. undertake.
举例： the driver failed to see the other car in time. 司机没能及时看见另一辆车。
i happen to know the answer to your question. 我碰巧知道你那道问题的答案。
2）动词+不定式 ；动词+宾语+不定式。
ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish…
i like to keep everything tidy. 我喜欢每件东西都保持整洁。
i like you to keep everything tidy. 我喜欢你使每件东西都保持整洁。
i want to speak to tom. 我想和汤姆谈话。
i want you to speak to tom. 我想让你和汤姆谈话。
3） 动词+疑问词+ to
decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tell
please show us how to do that. 请演示给我们如何去做。
there are so many kinds of tape-recorders on sale that i can't make up my mind which to buy.有这么多的录音机，我都拿不定主意买哪一种。
注意：疑问词带不定式在句中作成分时，谓语动词用单数。
the question is how to put it into practice. 问题是怎样把它付诸实施。
四、作表语。
不定式作表语表示具体动作或将来动作；①to be kind to the enemy is to be cruel to the people.
五、作状语。
1）目的状语
to… only to (仅仅为了), in order to, so as to, so(such)… as to… (如此……以便……)
he ran so fast as to catch the first bus. 他飞快地跑以便赶上第一班车。
i come here only to say good-bye to you. 我来仅仅是向你告别。
2）作结果状语，表事先没有预料到的，要放在句子后面。
what h**e i said to make you angry.
he searched the room only to find nothing.
3) 表原因 i'm glad to see you.
六、作定语。
⒈不定式作定语
不定式在句中作定语，置于被修饰的名词或代词之后。如：
①the next train to arrive is from washington.
②h**e you anything to be taken to your sister?
[省to 的动词不定式]
1） 情态动词 ( 除ought 外，ought to)：
2） 使役动词 let, h**e, make：
3） 感官动词 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作宾补，省略to。
注意：在被动语态中则to 不能省掉。
i saw him dance.
=he was seen to dance.
the boss made them work the whole night.
=they were made to work the whole night.
动词不定式的否定式]
tell him not to shut the window…
she pretended not to see me when i passed by. 我走过的时候，她假装没看见。
1、 "why not +动词原形"表达向某人提出建议 "为什么不……?干吗不……?
例如：why not take a holiday? 干吗不去度假？
2、it's for sb.和 it's of sb.
1）for sb. 常用于表示事物的特征特点，表示客观形式的形容词，如easy, hard, difficult, interesting, impossible等：
it's very hard for him to study two languages. 对他来说学两门外语是很难的。
2）of sb的句型一般用表示人物的性格，品德，表示主观感情或态度的形容词，如good, kind, nice, clever, foolish, right。
it's very nice of you to help me. 你来帮助我，你真是太好了。
4、不定式的特殊句型too…to… 1）too…to 太…以至于…
he is too excited to speak. 他太激动了，说不出话来。
5、部分动词后接不定式或动名词时，意义差别较大，应根据句子语境选择使用。
①forget,remember,regret后接不定式，表示现在或未来的动作，接动名词表示动作已经发生。如： 动名词与不定式语义不同的有
1、stop to do stop doing
2、 forget to do forget doing
3、remember to do remember doing
4、 regret to do regret doing
5 、try to do try doing
6、go on to do go on doing
7、afraid to do afraid doing
8、interested to do interested doing
例题 1、 forget doing/to do
forget to do 忘记要去做某事。 (未做)
forget doing 忘记做过某事。 (已做)
2、stop doing/to do
stop to do 停止，中断做某事后去做另一件事。
stop doing 停止做某事。
they stop to smoke a cigarette. 他们停下来，抽了根烟。
i must stop smoking.. 我必须戒烟了。
3、 remember doing/to do
remember to do 记得去做某事 (未做)
remember doing 记得做过某事 (已做)
remember to go to the post office after school.
记着放学后去趟邮局。
don't you remember seeing the man before? 你不记得以前见过那个人吗？
4、 regret doing/to do
regret to do 对要做的事遗憾。 (未做)
regret doing 对做过的事遗憾、后悔。 (已做)
5、try doing/to do
try to do 努力，企图做某事。
try doing 试验，试着做某事。
you must try to be more careful. 你可要多加小心。
i tried gardening but didn't succeed. 我试着种果木花卉，但未成功。
八年级上册英语语法讲解与练习
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八年级上册英语语法讲解与练习
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八年级上册英语语法讲解与练习
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