2、动词不定式复心中应注意的几个问题

(1)不定式作表语与“be + to do sth.”的异同。不定式作表语说明主语的内容或性质。

His job is to guard.(说明内容)

be + to do sth.(表示按计划要做的事)

(2)带不定式作宾语的词语。

下列词语常不定式作宾语：afford、promise、refuse、expect、hope、learn、offer、wish、want、fail、plan、agree、forget、like、prefer、decide、manage、try、arrange、determine、desire等。

下列动词后可接疑问词+不定式：teach、decide、wonder、show、learn、forget、ask、find、out、advise、discuss等。

(3)如何理解和使用不定式作宾补。

①动词see、watch、notice、hear、listen to、observe、feel、taste、smell、make、let、have等的宾补用动词原形，变被动时要加to,此时的不定式就是主语补足语。

②常用带不定式作宾补的几种情况：

主语 + ask / require / tell / order / force / get / want / like + sb.to do sth.

③主语 + think / judge / suppose / believe / consider /imagine/

consider / feel + sb. + to be/ to have done

④主语 + call on / upon / depend on / wait for / ask for + sb.+ to do sth.

(4)不定式作定语的特殊用法。

①下列词语后常接不定式作定语：chance、wish、right、courage、need、promise、time、opportunity、way、the first、the second、the last、the only等。

②不定式作定语和所修饰的名词在逻辑上有主谓关系。

There is no one to look after her.

③不定式与被修饰的名词在逻辑上有动宾关系。

She is now looking for a room to live in.

(5)不定式作状语的用法。

不定式作状语，修饰动词，在句中表示行为目的、结果、原因。only to do表示出人意料的结果。

We hurried to the classroom only to find none there .

in order(not)to,so as(not)to用来引导目的状语,enough,too, so… as to do, such + 名词… as to do作结果状语，如:The girl was so kind as to help the old man off the bus.

I’m not such a fool as to believe that.

(6)不定式的完成时的特殊用法。

①表示不定式中谓语动词发生的动作先于主句的谓语动词发出的动作。

The novel was said to have been published.

I regret to have been with you for so many years.

seem、appear、be said、be supposed、be believed、be thought、be known、be reported等动词常用于上面句型。

此外，glad、happy、satisfied、sorry、surprised、disappointed后也接完成时，但要注意与一般时的区别。

I’m sorry to keep you waiting for a minute.对不起，请稍等。(说话时还未等)

I’m sorry to have kept you waiting.对不起，让你久等了。(说话时已等了很久)

②不定式的完成时还可表示“过去本想做某事但未做”的虚拟语气。(A)should like to / would like to / would love to + 不定式的完成时。(B)was / were to + 不定式的完成时，表示该做某事或想做但未实现。(C)expect / hope / mean / promise / suppose / think / want/ wish + 不定式完成时，表示过去未曾实现的愿望。

(7)不定式的省略。　

①同一结构并列由and或or连接。

I want to finish my homework and go home.

I’m really puzzled what to think or say.

特例：To be or not to be,this is a question.

He is better to laugh than to cry.(表示对比)

②不定式作表语，其前面的主语从句中含有do时，后面的to省略。

What he did was lose the game.

③句中含有动词do时，but、except、besides、such as等后面to可省略。即“前有do,后省to”。

Don’t do anything silly, such as marry him.

④主句含有不定式，后面有rather than, rather than后省to。

⑤Why not、had better、would rather、can’t but等词后省to。如：

He could not but walk home.

(8)不定式的替代。

多用在同一句或联系紧密的对话中，为了避免重复，作宾语或主补，宾补的不定式再次出现时，to后的内容常承前省略(只保留to即可)。但如果承前省略的不定式有助动用的have或be任何形式，后应该保留原形be或have。如：

Susan is not what she used to be.

-You came late last night. You ought to have finished your

homework.

-I know I ought to have.

常见的有：I’d like / love / be happy to.

1、非谓语动词的句法功能

3. -If he ___________, he ________that food.

-Luckily he was sent to the hospital immediately.(NMET　 93)

A.was warned; would not take

B.had been warned; would not have taken

C.would be warned; had not taken

D.would have been warned; had not taken

解析：答案为B。本题考查的是条件状语从句与主句表示与事实相反时虚拟语气的用法。根据下一句语境可知，他事先并没有得到警告，表示过去时间的虚拟语气，故选B。

2. I didn’t see your sister at the meeting. If she ___________, she would have met my brother.(NMET　 94)

A.has come　　　 B.did come　　　 C.came　　　 D.had come

解析：答案为D。本题考查的是if条件句中的虚拟语气。题意是：我在会议上没看到你姐姐，故你姐姐没来。因此如果“她来了”与事实相反，前面一句交代了虚拟语气的时态是一般过去时的虚拟，所以if从句中用had+过去分词。

选择填空

1. When a pencil is partly in a glass of water, it looks as if it _______. (NMET　 95)

A.breaks　　 B.has broken　　 C.were broken　　　 D.had been broken

解析：答案为C。本题考查的是as if 引导的让步状语从句中的语气问题，as if引导的状语从句如果与事实一致，不用虚拟语气，如果与事实相反，应用虚拟语气。题中“当铅笔的一部分浸在水中，铅笔看上去好像断了”。而实际上铅笔并未断，与事实相反，前半部分陈述是一般现在时，因而本句是对一般现在时的虚拟，用were broken。

3、虚拟语气在其他场合的运用

(1)虚拟语气在as if/as though、even if/even though等引导的表语从句或状语从句中，如果从句表示的动作发生在过去，用过去完成时；指现在状况，则用一般过去时；指将来状况则用过去将来时。如：

He did it as if he were an expert.

Even if she were here, she could not solve the problem.

(2)虚拟语气用于定语从句中。

这种从句常用于句型“It is (high)time (that) … ”中，定语从句的谓语动词用一般过去时(be用were)或should + 动词原形，意思是“(现在)该……”。如：

It’s time that I picked up my daughter.

It’s high time we were going.

(3)虚拟语气用在if only引导的感叹句中。如：

If only I were a bird.

If only I had taken his advice.

(4)虚拟语气在一些简单句中的运用。

①情态动词的过去式用于现在时态时，表示说话人谦虚、客气、有礼貌或语气委婉，常出现在日常会话中。如：

It would be better for you not to stay up too late.

Would you be kind enough to close the door?

②用于一些习惯表达法中。如：

Would you like a cup of tea?

I would rather not tell you.

2、虚拟语气用于名词性从句

(1)虚拟语气在宾语从句中的运用。

①“wish + 宾语从句”表示不能实现的愿望，译为“要是……就好了”等。表示现在不能实现的愿望，从句中的谓语动词用一般过去时；表示将来不能实现的愿望，从句中的谓语动词用“would/could + 动词原形”；表示过去不能实现的愿望，从句中的谓语动词用“had + 过去分词”或“could(should) + have + 过去分词”。如：

I wish it were spring all the year round.

I wish I had known the answer.

I wish I could fly like a bird.

②在表示建议、要求、命令等的动词suggest、advise、propose、demand、require、insist request、command、order等后的宾语从句中，谓语动词用should + 动词原形或是动词原形。如：

She suggested we (should)leave here at once.

The doctor ordered she should be operated.

(2)虚拟语气在同位语从句和表语从句中的运用。

作表示建议、要求、命令等的名词advise、idea、order、demand、plan、proposal、suggestion、request等的表语从句和同位语从句，从句中的谓语动词用“(should) + 动词原形”。如：

His suggestion that we (should)go to Shanghai is wonderful.

My idea is that they (should)pay 100 dollars.

(3)虚拟语气在主语从句中的运用。

在主语从句中，谓语动词的虚拟语气用“should + 动词原形”的结构，表示惊奇、不相信、理应如此等。如：

It is necessary(important, natural, strange, etc.)that we should clean the room every day.

It was a pity (a shame, no wonder, etc.)that you should be so careless.

It will be desired(suggested, decided, ordered, requested, proposed, etc.)that she should finish her homework this afternoon.

注意：这种从句表示的是事实。如果说人对这种事实表现出惊奇的情感，就可用虚拟语气。反之，如果不表示惊奇等情感，that从句也可用陈述句语气。如：

It is pity that you can’t swim.

1、虚拟语气用于条件状语从句中

　　 (1)表示与现在事实相反的假设，条件状语从句中的谓语动词用“过去式(be动词的过去式用were)”，而主句中的谓语动词用“would / should/ could / might + 动词原形”。如：

If I were a boy, I would join the army.

If the had time, she should go with you.

(2)表示与过去的事实相反，条件状语从句中的谓语动词用过去完成时，主句中的谓语动词则用“would / should / might / could + have +过去分词”。如：

If he had taken my advice, he would have succeeded in the competition.

(3)表示与将来事实相反，条件状语从句中的谓语动词一般过去时或should(were to) + 动词原形，而主句中的谓语动词则用would / should/

could might + 动词原形。如；

If it were to rain tomorrow, the football match would be put off.

(4)当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，动词的形式要根据它所表示的时间作相应调整。如：

If they had worked hard, they would be very tired.(从句说的是过去，主句指的是现在)

以下表格是虚拟语气用于条件状语从句中时，主句和从句谓语动词的形式：

有时侯在使用时可省略if,句子则可换成下列形式，即“were / had / should +主语”。如：

Were I a boy, I would join the army.

Had he taken my advice, he would have succeeded.

Were it not for the expense, I would go to Britain.

3. I hate __________ when peope talk with their mouths full.(NMET　 98)

A.it　　　　　　 B.that　　　　　　 C.these　　　　　 D.them

解析：答案为A。本题考查的是形式宾语的用法。题意为“我讨厌人们谈话时嘴里塞满东西”。该空白处没有任何含义，而且已经用了when连接该宾语从句，所以此处只填一个形式宾语it。

2. -I drove to Zhuhai for the air show last week..

-Is that _________ you had a few days off ? (NMET　 99)

A.why　　　　　 B.when　　　　　 C.what　　　　　 D.where

解析：答案为A。此题考查的是从句的用法。根据题意“我上周开车去珠海看航空展去了。”下面一句接着问：“那就是你为什么离开的原因吗？”故用why引导表语从句表示原因。