动词不定式to do 用法集合
动词不定式to do
1.表将来（要去做，还未做）
2.常用作目的状语，“为了”
目录：
1.否定式
2.动词不定式的时态、语态及意义动词
3.不定式的句法功能
4.动词不定式的主动形式表示被动意义
1.否定式
其否定式在to do前加否定词，即，not to do。
例：Not to get there in time is your fault.没有按时到那是你的责任。
My teacher told me not to be late again.我的老师告诉我不要再迟到了。
2.动词不定式各种时态下的主动语态与被动语态
注意：不定式没有人称和数的变化，但有时态和语态的变化，不定式可作主语、宾语、表语和定语，但不可作谓语。不定式的逻辑主语常用“for+代词或代词宾语”充当。
2.1不定式的时态界定。
如何判断下列不定式与谓语动词之间的先后关系？
我们来看两个例句，
1.My mum seemed to have known everything.
其中，to have known everything发生在谓语动作seemed之前。
2.She is well-known to have been to many countries.
其中to have been to many countries发生在谓语动作is well-known之前.
因此，我们得出一个【结论】，即，不定式完成式to have done主要表示发生在谓语动作之前的动作或状态。
2.2不定式的语态比较
一般式：
如，1.I'm excited to go to China. （to go to China主动语态)
2.She doesn't like to be treated as a bird in cage. (to be treated as a bird in cage被动语态)
完成式：
如，1. I'm sorry to have kept you waiting so long.
(to have kept you waiting so long，用的是主动语态)
2.The work seems to have been finished before the deadline.
(to have been finished before the deadline，用的是被动语态)
进行式：
如，I am very delighted to be working with you.
（to be working with you，用的是主动语态)
3.1不定式的句法功能-主语
不定式作主语时,一般表示具体的、个别的、一次性的或具有将来意义的动作。
如，To see is to believe.眼见为实
To help the poor is our duty.帮助穷人是我们的责任
不定式结构通常比较长，为了使表达更清晰明了，我们常用it作形式主语，代替真正作主语的不定式，以下四种句型结构，在初中阶段已经见过了，我们来回顾一下吧：
1.It+谓语 +宾语及其他动词不定式
例如，
It makes me sad to think about it. 想到它我就悲伤。
It does you a lot of benefits to swim in the rivers.在河里游泳对你很有好处。
2. It+be + 表语动词不定式
例如，
It was right to give up smoking.放弃抽烟是正确的。
It was quite beyond me to help him.我没能力给他提供帮助。
3. It+be + 表语 +of…动词不定式
例如，
It is very kind of you to help me.您能帮助我，真是太好了。
It was careless of him to make such a mistake.他犯这样的错误，太粗心了。
4. It+be + 表语带逻辑主语的动词不定式“for sb. to do sth.”
例如，
It is important for you to attend that meeting.你参加那个会议很重要
It is a good idea for us to work while studying.就学期间打工是个好主意。
3.2不定式的句法功能-宾语
作宾语，我们常见动词的宾语与介词的宾语，我们来看看以下句型都熟悉了吗？
①主语+谓语+宾语（不定式）
l 常见动词：
l 三个希望两答应(hope, wish, want, agree, promise)
l 两个要求莫拒绝(demand, ask,refuse)
l 设法学会做决定(manage, learn, decide)
l 不要假装在选择(pretend, choose)
例如，I hope to see you soon.
She refused to go out with me.
The dog managed to escape from the burning building.
He pretended to listen to the teacher’s speech.
②主语+谓语动词+宾语(wh-疑问词+动词不定式)
例如，
He asked how to get to the station.他询问如何去车站。
I don't know whether to go or stay.我不知道是去还是留。
可用于这一结构的动词，比如，ask, decide, know, remember, forget, explain, wonder等。
③主语+谓语动词+it +宾语补足语+宾语(动词不定式)
用it作形式宾语，而把真正的宾语，即，不定式放到后面.
例如，
He considered it better to start now. 他认为最好现在就开始。
I think it necessary to carry on the experiment.我认为有必要继续做这个实验。
I consider it my duty to appreciate you.我认为向你表达谢意是我的责任。
l 可用于这一结构的动词，比如：
believe认为，相信, consider 考虑，斟酌；认为, count看作，认为,
feel觉得，相信, find发现，发觉，认为, guess猜到；认为,
imagine料想，认为，想象,judge判断，认为；评判,
know 认识到，懂得； prove证实，证明；, realize 了解，意识到，认识到，
see认为，发现，看见, suppose推断，料想，猜想；假设,认为，相信，
suspect猜想，认为，怀疑, think想，认为,
understand理解，懂得；了解，明白，
report报道；据说，公布,show示，表明；给……看,declare宣布，声明,
deny否认；拒绝承认,等等。
哈哈，有没有发现，一大堆的跟主观意识有关的认为，觉得，在这里？
④不定式作but和except的宾语时，其前若有do动词,则要省略to.
例如，She could do nothing but cry.她除了哭别无他法。
3.3不定式的句法功能-表语
作表语，当然得放在系动词后，我们常见句型如下，
①主语+be +动词不定式作表语
举例，
His dream is to be a lawyer.他的梦想是成为一名律师。
The only choice is to wait. 唯一的选择就是等。
To spread knowledge is to spread happiness. 传播知识就是传播幸福。
②主语部分有动词do时，表语不定式扩展do的含义，可不带to。即，句型结构为，主语+be+动词不定式作表语不带to。
例如，
All they could do is keep studying. 他们所能做的就是继续学习。
What you can do is wait and see. 你能够做的就是等着瞧。
③疑问词 how/what/when/where/which等加不定式结构作表语。主语+be+(疑问词+动词不定式作表语)
例如，
The point is how to control yourself.关键在于如何自控。
The question is where to find the answer.问题是哪里去寻找答案。
3.4不定式的句法功能-宾补
此处所用的五大基本句型，即，主谓宾宾补。
(1) 在feel, hear, listen to, look at, notice, observe, see, watch, have, let,make等词后的宾语补足语中，不定式不带to。但是这些句子如果变成被动结构时，就必须带to。
例：
I saw him enter the room just now. 我刚刚看他进了房间。
He was seen to enter the room just now. 他被人看到刚刚进了房间。
来一个省略to的不定式的口诀 ，“吾看三室两厅一感觉半帮助”
l 吾看：五看see, look at, watch, notice, observe
l 三室：三使make, let, have
l 两厅：二听hear, listen to
l 一感觉：一感feel,
l 半帮助：帮助help (help sb do ; help sb to do，可省可不省)
（2）"to be +形容词/名词”. believe, consider, declare, feel, find,judge, know, prove, suppose, think等。
熟悉的画面来了，又见那堆跟主观意识有关的‘认为，觉得’类动词。
例如：I believe him to be honest. 我相信他是诚实的
I judge her to be a judge.我认为她是个法官。
（3）变为被动结构，不带to的不定式作主语补足语必须带to（被动中保留 to）：
例： 主动：They had seen her grow up. 他们看着她长大。
被动: She had been seen to grow up.她被看着长大。
（4）作主语补足语的不定式可用完成式和进行式。
例：He is said to have won the gold medal.据说他赢得了金牌。
to have won 是完成式。
（5）have somebody do something/ make somebody do something/ get somebody to do something的区别。
have-期望别人为自己做某事,份内该做的事情。
make-用权力迫使别人做不情愿做的事情
get-劝说别做我们所希望的事情，有一定的难度。
接下来，我们扩充一下省略to的其他情况：
1. than之后常接不带to的不定式,
1）would rather do ...than do 宁愿做……也不做
2）rather than do
常见于，prefer to do....rather than do 结构，“更喜欢做....而不是做。”
3）do nothing than 宁可什么不做也不
注意：
know better than to do是个短语,"懂得不该去做某事;不会蠢到去做某事"
I know better than to do such a foolish thing.我不会蠢到去做这样的傻事。
2. but结构,
1）cannot but 不能不，不得不，只能，
He cannot but agree他不得不同意。
2）cannot choose but 不得不，没有选择的余地，只能做。
I cannot choose but wait. 我别无选择，只好等待。
3）cannot help but 不能不，不得不，不禁，禁不住（表示无法控制自己的行为或情感，不由自主地做某事或产生某种感受。）
Tonight, I cannot help but marvel at how far we have come together.
今晚，我不禁对双方交往的长足进展感到惊叹。
4）do nothing but 除了做某事之外什么都不做，只有做
They do nothing but bow to play mobile phones.
他们什么也不做，只是低头玩手机。
5）have nothing to do but除了做某事以外别无选择，表示除了某个动作或活动以外，没有其他事情可做。
You have nothing to do but wait. 你除了等待，没有别的办法。
3.一些固定搭配, let fly发射;放飞/let go松手;放开/make do将就；凑合；I've heard say我听说
4.当as well as前是带to的动词不定式时,其后接的动词不定式不带to
例如，I came to see you as well as learn the truth.
3.5不定式的句法功能-定语
l 作定语(常置于名词之后)由only, last, next 序数词或形容词最高级修饰的名词常用不定式作定语；不定式还可用作名词或不定代词的定语。
例：
have the ability to do sth有做某事的能力
have an attempt to do sth 试图去做某事
have something to do 有事情需要去做
the only one to come 唯一来的人
have something boring to say 有一些无聊的事要说
He is always the last one to leave the office.他总是最后一个离开办公室。
注意：动词不定式to后所接动词若是不及物动词，不定式后应有的介词。
例如:
I haven't decided which city to stay in. 我还没决定住在哪个城市。
I found no one to go with. 我找不到可以一起去的人。
l 另，有几项用法：
①不定式作定语有时几乎相当于一个定语从句，大多用于表示即将发生动作.
例如， The problem to be discussed tomorrow is of great interest.
明天要讨论的问题很有意思。
可以定从表示为，
The problem which will be discussed tomorrow is of great interest.
②不及物动词的不定式形式与被修饰词构成逻辑上的动宾关系,作定语的不定式是不及物动词,动词后应加上必要的介词，使之能与逻辑宾语搭配;有时不定式所修饰的名词或代词是不定式动作的地点、工具，不定式后也要加介词。
例如， a pen to write with
③不定式修饰的名词是time, place, way时,其后习惯上省略介词.
例如，This is the best way to work out the problem (in).
We are looking for a place to lie (in).
④ 表示将来意义或被修饰词是序数词,最高级, the only/the last等或被该类词修饰时多用不定式作定语,
That is the only way to solve the problem.
3.6 不定式的句法功能-作状语
不定式作状语，多表示目的、原因、结果、条件等,一般位于句首，有时也可位于句中或句末。为了强调，还可以用in order to do…或者so as to do 。
例如:He went to America to learn Finance.(表目的)
He hurried to the bus stop only to find the bus had left. (表结果)
He cried to hear the bad news.(表原因)
不定式作原因状语：
①主语+表示情感的不及物动词作谓语+不定式作原因状语
例如:He shouted to be noticed. 他大声叫以引起注意。
②主语+be+表示情感的形容词或过去分词作表语+不定式作原因状语
例如: He was delighted to hear from his girl friend.
他收到女朋友的来信很高兴。
③主语+be+说明人的行为或品质的形容词表语+不定式作原因状语
例如: He is so warm-hearted to help you with your math.
他是如此热心帮助你学习数学。
3.6 不定式作结果状语
l 1.too...to…..太...而不能
如: It is too heavy to take off.
2. not/never too...to.表示肯定意义
如: It is never too old to learn.
3. only to do 意想不到的结果作结果状语
如: He tried on the dress ,only to find it didn’t fit.
4. so... as to do 如此…以致
如: I was so tired as to fall asleep during the trip.
5. such+名词 as to do 如此…以致
如: I was such an excellent woman as to receive a big reward.
6. in order to do 为了做
如: I have collected plastic bags in order to protect the planet.
易混点辨析：
动词不定式-主动形式表被动含义
l 1.在"adj+to do"结构中,不定式多用主动语态,常见形容词: hard, difficult,easy, fit, cheap, expensive,等
如:The T-shirt is fit to wear.
l 2.在there be结构中,倾向于用不定式主动语态表示被动意义.
如:There are always many chores to do in the house.
l 3.固定搭配用不定式主动语态。
如:She is not to blame. (be to blame 该受责备，应承担责任)
3.7不定式的句法功能- 作独立成分
l 常用作独立成分的不定式短语，比如，
老实说，坦白说
to tell you the truth、to be honest、to be frank 、to speak frankly
首先，一开始 ，最初
to begin with、to start with
总而言之 to sum up
无疑，诚然，当然 ，的确 to be sure/certain
更糟糕的是 to make matters/things worse
更不用说，谈不上 not to mention
不用说 needless to say
如:To speak frankly, I don't like your attitude.
坦率地说，我不喜欢你的态度。
总结summary
不定式：
主宾表定状补，it形宾与形主；
若改宾从从句无；留疑问词接to do；
感官使役甩不甩to；须看语态被与主。
