英语语法讲座系列 Infinitive 不定式

I. 构成与特征 不定式（Infinitive） 动词不定式是动词的一种非限定形式， 由“to+动词原形”构成，在句中起名词、形容词或副词的作用，同时也保留动词的一些特征，可以带宾语或状语。

II. 功能 作主语 作宾语 作定语 作状语

1.作主语 To persevere means victory! 坚持就是胜利！ For him to admit his mistake is not easy. 要他承认错误不是容易的。（带逻辑主语） Never to have made any mistake is impossible. 从不犯错误是不可能的。（带副词） How to make our life longer is a big problem. 怎样使我们活得更长久是个大问题。（带关系副词）

1.作主语 但在很多情况下，特别是在口语中，我们常用代词 it 代替作形式主语（但不可用 that 作形式主语）。不定式则移到谓语之后，这样使句子显得比较平稳。

T 2.F e.g. 1. It is very difficult to drive in the mountains. 2. That is very difficult to drive in the mountains. 2. It is very difficult to drive in the mountains. 3.It is not an easy thing to master a language. To master a language is not an easy thing.

Note ： (1)不定式作主语时，在很多情况下都可用动名词代替 e.g. Hesitating means failure. 但作主语的不定式是固定的说法或表示较强烈对比或某些具体情况等，通常不用动名词替代。 e.g. To teach is to learn. （对比） To finish this job in one day is impossible. (某次具体情况)

1.作主语 （2）有时候，作主语的不定式相当于一个条件从句。 e.g.To love others is to be loved. If you love others, you will be loved by others. back

2.作宾语 He offered to help us . 他提出要帮助我们。 Children love to listen to fairy tales. 孩子们喜欢听童话故事。 能以不定式作宾语的动词: try, ask, offer, want, like, wish, hate, prefer, continue, manage, start, promise, forget, mean, intend, begin, agree, care, choose 等。

他忘记给儿子买过生日礼物了。（做过忘记了) 既可跟不定式又可跟动名词的动词 1）意义不变的有： begin,continue,prefer,start,hate,like, etc. e.g.He started to do/doing his experiment after his dinner. 2) 意义不同的有： stop,remember,forget,regret,try,mean,go on etc. e.g.He forgot to buy a present for his son. He forgot buying a present for his son. 他忘记给儿子买生日礼物。（没有做） 他忘记给儿子买过生日礼物了。（做过忘记了)

(1) 动词+ how / what / where / which / when/why + 不定式 2.作宾语 Note: (1) 动词+ how / what / where / which / when/why + 不定式 这类动词中最常用的是： ask, decide, know, tell, teach, find out, learn etc.

We must decide whether to go or stay. e.g. We must decide whether to go or stay. No one could tell me where to get the book. She couldn't think what to say. They will teach us how to repair farm tools. I didn't know when to switch the machine off. I showed her which button to press.

(2)另外，在某些复合宾语中，常用一个it 代表不定式，而把不定式放到后面. e.g. They found it impossible to get everything ready in time. She thought it unnecessary to argue with him about it. I consider it better not to go.

3.作定语 （1）动词不定式与其所修饰的词之间往往有动宾关系，如果这个不定式是不及物动词，它后面就应该有必要的介词。

Do you have anything more to___ (say)? I want to get something to ___(read) during the vacation. read She is a very nice person to ____(work). work with There is nothing to____( worry). worry about

Thank you for giving me the chance to make the speech. (2)有些名词后常跟不定式作定语 time 时间 chance 机会 way 方法 reason 理由 effort 努力 right 权利 e.g. Thank you for giving me the chance to make the speech. 谢谢你给我发言的机会。 Is that the best way to solve the problem? 这是解决问题的最好办法吗？

3.作定语 The plans to be made are of vital importance. （3）不定式可以修饰作主语的名词，相当于 一 个定语从句，表明动作即将发生。 e.g. The plans to be made are of vital importance. 要制定的计划至关重要。 The conference to take place next month is bound to be a great success. 下个月的会议一定很成功。

4.作状语 不定式作状语的情况很多，可以表示目的，结果或原因等。 （1）表示目的 不定式也常用在so as (to) 或 in order(to) 后,与它合起来作状语用, 否定式 in order not+ 不定式或 so as not +不定式。

4.作状语 The whole family went to beach to spend their weekend. 全家人去海边度周末。 To save the child, he laid down his life. 他为了抢救那个儿童而献出了自己的生命。 Let’s hurry so as not to be late for the meeting. 咱们快点走，免得开会迟到。 4.作状语

4.作状语 (3)表原因 (2)表结果 He left, never to return. 他走了,再也没有回来。 She lived to be 100 . 她活到一百岁。 (3)表原因 We jumped with joy to hear the news. 我们听到这个消息后高兴得跳了起来。

4.作状语 (4)表说话人的态度，对整个句子进行解释，在句中作独立成分。 e.g. 1)To tell you the truth, I am not in favor of your plan. 说实话，我不赞成你的计划。 2) To be frank, we don’t trust him. 坦白地说，我们不信任他。

4.作状语 so… as to 引导的是结果状语从句，so 后面跟形容词或副词，表示“到某种程度以致…”。 1. so as to 引导的是目的状语从句，相当于in order to , 表示“以便”； so… as to 引导的是结果状语从句，so 后面跟形容词或副词，表示“到某种程度以致…”。 2. so as to 前面可用逗号，而so … as to 则不可。 5)so as to 不同于so … as to

e.g The test questions are kept secret, so as to prevent cheating . 考题保密，以防作弊。 露丝不会那么粗心，以致于把钢笔忘了带。(=so …that) The test questions are kept secret, so as to prevent cheating . Rose wouldn’t be so careless as to forget her pen . 作状语结束

III.不带to的动词不定式 1.在助动词和情态动词 “do,will,shall,would,should,can,may,must etc.”之后： e.g. You must do as you’re told. He will probably object.

III.不带to的动词不定式 2.在“使役动词 let, make, have etc.+宾语”之后 e.g.We can’t let this go on. He won’t have us criticize his work. 当使役动词为被动语态时，不带 to 不定式转为带to不定式： e.g.John made her tell him everything. She was made to tell him everything.

III.不带to的动词不定式 3.在“感觉see,hear,observe,notice,feel ,watch+宾语“之后： e.g.I watched him eat his breakfast. We feel the house shake. 当感觉动词为被动时态时，不带to不定式转为带to不定式： e.g.They saw him enter the building. He was seen to enter the building.

III.不带to的动词不定式 4.在help（或help+宾语）之后，既可以用不带to不定式，也可用带to 不定式。 e.g. I’ll help you (to) solve it. 5.在介词except/but之后（如果except/but之前有动词“do”的某种形式，其后通常用不带to不定式，否则带to。 e.g.They did nothing except work. There’s no choice but to wait.

III.不带to的动词不定式 6. 在“why/why not……?”之后 e.g.Why spend such a lot of money? Why not wait for a couple of days? 7.在“had better, had best ,would rather, would rather…than, would sooner, cannot but ,would sooner…than, do nothing but 等结构后面。

III.不带to的动词不定式 You’d better remain where you are. e.g. You’d better remain where you are. 你最好待在你现在待的这个地方。 I would (had) rather not see him. 我宁愿不去见他。 They would rather try and fail than give up the plan. 他们宁愿尝试不成功也不愿放弃这个计划。

III.不带to的动词不定式 8.在go, come 和 run 后可省略 to，直接用另一个动词，多用于表示命令，建议,请求或意愿的句子中。 e.g.Come have a drink with us. (=Come to have…) I’ll go see my sister.(=go to see…) Let’s go hear a concert.

III.不带to的动词不定式 9.rather than 或sooner than 位于句首时，其后的动词不用to。 e.g. 1.Sooner than run the risk of losing more money, he agreed to the term. 2.Rather than travel by air, he preferred a train on his tour.

III.不带to的动词不定式 10.为避免重复，不定式可省略去to。 e.g. He was at a loss as to what to think and say. 但是如果两个不定式表示对照或对比，则不可省去to。 e.g. To die or not to die -- that is the question. He hasn’t decided whether to go home or to stay at school during the vacation.

go change to give up eat stay We had better (go) there by air. She could do nothing but (change) her name under the circumstances. He was made (give up) his dream. I watch him (eat) his breakfast. In fact ,she would rather leave for San Francisco than (stay) in Los Angeles. go change to give up eat stay

IV.不定式符号to 和介词to 的辨别问题 英语中有相当数量的常用短语，其最后一个词 是 to ；to 既可以是介词，也可以是不定式符号。作为介词，to后面接名词或动名词; 作为不定式符号，后面须接动词原形，不可混淆。下面提供七种类型含介词to的搭配。

含介词to的搭配 1. 动词+介词to agree to (同意)，admit to（承认）， attend to（注意、照顾）.come to（到达，涉及到），contribute to (承认)，object to （反对），refer to (提及)

含介词to的搭配 2.动词+名词/代词+介词to attribute…to（归因于), apply…to（致力于）, accustom…to (使习惯于)，confine…to (限于…范围内)，dedicate…to（奉献），prefer…to （喜欢），owe…to （归功于）

含介词to的搭配 3. 动词+ed 分词+介词to be accustomed to （惯于）,be devoted to （致力于），be used to （习惯于，适应于）， be reduced to （使变小），be reconciled to（甘心于，顺从） 等。

含介词to的搭配 4. 动词+副词小品词+介词 to get down to （开始认真做某事），look forward to （盼望），get near to （几乎，接近于，face up to （勇敢地面对）等。 5. 形容词+介词to similar to （类似）,loyal to （忠于）， deaf to（不愿意听），superior to （优于、胜过），sensitive to （敏感），preferable to （较合人意）等。

含介词to的搭配 6. 名词+介词to objection to（反对）,answer to（回答、答复）,limit to （限度），aid to (辅助) indifference to （不关心），key to （解答，关键）等。 7. 以介词to 结尾的复杂介词 according to（根据，按照）,as to（关于）,owing to （因为，由于），thanks to （由于，多亏），in addition to （除… 之外）等。

You must accustom yourself to ( get ) up early. We are looking forward to (see) you again. He used to (smoke ) a pipe. He was reduced to (beg) for food. She is working hard to (earn) money. getting seeing smoke begging earn

OVER!