2021届河北衡水高中英语新高考语法复习讲义（067）疑问词与动词不定式连用常考知识点总结整理疑问词what，who，which，when，where，how 和连词whether 之后，可跟一个带“to”的不定式，构成一个特殊的动词不定式短语，可在句中作主语、宾语和表语。

如：
How to solve the problem is very important.
如何解决这个问题是非常重要的。

（主语）
Ken didn't know what to say.
肯不知道该说什么。

（宾语）
The question is where to find the source of water.
问题是在什么地方能找到水源。

（表语）
例题：
—I don't know with this problem. It's too hard.
—You can ask Mr. Wang for help.
A. which to do
B. when to do
C. what to do
D. how to do
【答案选C】不定式前加疑问词构成不定式短语作宾语。

•for+名词或代词宾格+动词不定式
在动词不定式的复合结构中，for本身无意义。

for后面的名词或代词形式上是for的宾语，但在意义上是不定式的逻辑主语。

这种不定式在句中可作主语、表语、宾语、定语和状语等。

1）作主语。

如：
It is necessary for us to learn from each other.
我们必须互相学习。

It is difficult for present⁃day readers to understand why the novel Sister Carrie was withdrawn from circulation at the beginning of the 20th century.
今天的读者难以理解为什么小说《嘉莉妹妹》在二十世纪初曾被停止发行。

It is necessary for us to learn a foreign language.
我们学一种外语是必要的。

2）作表语。

如：
The popular science books are for middle school students to read.
这些科普读物是给中学生看的。

It is for you to decide. 这得由你决定。

What we want is for you to understand the matter clearly.
我们所希望的是你更清楚地了解这件事。

Having a trip abroad is certainly good for the old couple, but it remains whether they will enjoy it. （2002年高考全国卷）
A. to see
B. to be seen
C. seeing
D. seen
【答案选B】考查不定式作表语。

remain前面的it是形式主语，whether引导的从句是主语从句，是真正的主语。

remain 在此句中用作系动词，后接不定式作表语，表示将来的动作。

要填入的see 与whether they will enjoy it存在动宾关系，所以要用被动语态。

3）作宾语。

如：
I found it impossible for him to do the job alone.
我发现他一个人干这活是不可能的。

We consider it necessary for him to answer the question.
我们认为他有必要回答这个问题。

This has made it necessary for agriculture and industry to develop very quickly.
这使得工业和农业必须快速发展。

1. The headmaster told us at the Science Museum on time.
A. arrive
B. arrives
C. to arrive
D. arriving
【答案选C】tell sb. to do sth. 告诉某人去做某事。

2. The chairman thought necessary to invite Professor Smith to speak at the meeting.
A. that
B. it
C. this
D. him
【答案选B】动词不定式to invite Professor Smith to speak at the meeting是句子的宾语，用it作形式宾语。

4）作定语。

如：
There is a lot of work for us to do.
有很多工作要我们去做。

It's a good chance for you to go.
这是你去的好机会。

We have several PC models for you to choose from.
我们有好几种计算机机型供你从中挑选。

I'm going to the supermarket this afternoon. Do you have anything ?
A. to be buying
B. to buy
C. for buying
D. bought
【答案选B】考查不定式作定语。

“要买”的动作还没有发生，应该选用不定式表示将来。

5）作状语。

如：
I sent him some pictures for him to see what Paris is like.
我送他一些图片，让他看看巴黎的样子。

The film was good enough for me to watch many times.
这部电影好到我愿意看多遍。

The text is too long for us to learn by heart.
课文太长，我们背不下来。

在表示人、物性质、特征等的形容词的后面，常用of引出不定式的逻辑主语，这些形容词一般有：absurd荒唐的，bold大胆的，brave勇敢的，careful仔细的，careless粗心的，clever 聪明的，considerate 考虑周到的，courageous 有勇气的，cruel 残酷的，foolish 愚蠢的，good友善的，grateful感激的，honest诚实的，
impolite无礼的，kind善良的，nice正派的，polite有礼貌的，right 正确的，rude粗鲁的，silly傻的，stupid笨的，thoughtful体贴的，wicked邪恶的，wise明智的，wrong错误的等。

如：
It is very kind of you to help him every day.
你每天帮助他，你真好。

It was brave of you to do that.
你那样做真勇敢。

It was stupid of him to make such a mistake.
他真蠢，犯了那样的错误。

In our childhood, we were often by Grandma to pay attention to our table manners.
A. demanded
B. reminded
C. allowed
D. hoped
【答案选B】四个选项中，能带动词不定式作宾语补足语的只有remind和allow；其次，根据语境判断，此处应理解为“被提醒要……”。