2 不定式的几个主要句型及应注意事项

1 不定式的否定式和《asktellsb.notto do sth.》句型

不定式的否定式的句型是《not +不定式》,经常和asktell…)to do sth.句型连用。尤其在间接引语中。

My father said to me,“Don't be late.

爸爸对我说:“不要迟到”。

变为间接引语:

My father toldaskedme not to be late.

I said to him,“Don't open the window.

我对他说:“不要打开窗户”。

变为间接引语:

I asked him not to open the window.

比较

不定式的否定式和否定句的区别否定句:

I didn't ask him to open the window.

我没有拜托他打开窗户。

不定式的否定式:

I asked him not to

open the window.

我请他不要打开窗户。

必背!

ask a question           提问题

ask sb. for help          请求某人来帮助

ask sb. to come         请某人来

2“疑问词+不定式”结构

I know how to cook.

我知道如何煮。

I don't know what to buy for you.

我不知道要买什么东西给你。

不定式可以和疑问代词whowhatwhich及疑问副词whenhowwhere连用,构成不定式短语,在句中担当主语、宾语、表语等成分。

1.作主语

What to do is a big problem.

做什么是个大问题。

2.作宾语

I know how to use the computer.

我知道如何使用计算机。

3.作宾语补足语

Can you tell me which way to go

你能告诉我走哪条路吗?

I didn't find out when to leave.

我不清楚何时出发的。(介词宾语)

He taught me how to read it.

他教过我如何读它。

She will tell me where to go.

她会告诉我去什么地方的。

4.作表语

The question is how to get there.

问题是如何到达那儿。

3 不定式中省去to的情况

1.当两个或两个以上的不定式并列在一起时,第一个不定式带to,后面的不定式往往省略to,参见下文首

例;但是,如果是在对照的场合,就不可以省去to

参见下文后例。

He told me to finish my homework andto hand it in.

他对我说:“完成作业并把它交上去”。

It is better to laugh than to cry.

笑比哭好。

2.在感官动词seewatchlook athearlisten tofeel和使役动词makehavelet等所接的宾语中(不定式)作宾语补足语),不定式应省去to。但是在被动语态中,则to不能省掉。

注意

疑问词+不定式作宾语和宾语补足语时,常与下列动词连用:knowshowteachtellfind outlearndecideforget等。

句型转换

简单句:

I don't know what to do.

复合句:

I don't know what I should do.

我不知道要做什么。

how的用法

How old are you

你多大了?

How are you

你好吗?

How do you do

你好吗?

How tall he is

他多高啊!

(感叹句)

How did you come here

你怎么来这儿的?

(对状语提问)

I saw him dance.

被动:He was seen to dance.

我看到他跳舞。

The boss made them work the whole night.

老板迫使他们工作了一整夜。

被动:They were made to work the whole night.

Let me listen to you sing the song.

让我听你唱这首歌。

被动:You will be listened to sing the songby me.

3.help后面的不定式可带to,也可不带to

I often help himtoclean the room.

我常常帮他打扫房间。

4 不定式中原形动词的省略

为了避免重复,口语中常可省去与前边动词重复的动词原形,而只留下to

Would you like to go with me

你愿意和我一起去吗?

I'd like to.我愿意。

If you don't want to read ityou don't need toread it.

如果你不愿意读它,就不必去读。

5 wantwishpromisehope +不定式

I want you to go there.           我想要你去那儿。

I promise to sing a song.         我答应唱一首歌。

I hope to meet you again.       我希望能再遇到你。

1.wantwishto do sth.》和《wantwishsb. to do sth.

两个句型意思不同。前者是主语想去做某事。后者是宾语sb.去做某事。wishwant用法一致。

He wantswishesto start at once.

他想要(希望)马上开始(出发)。

He wantswishesme to start at once.

他想要(希望)我马上开始(出发)。

2.promise to do~与promise sb. to do sth.这两个句型都可以用

He promised to attend the meeting.

他答应去开会。(主语He去参加会议)

He promised us to attend the meeting.

他答应我们,他去参加会议。

(不是宾语us去参加会议,而还是主语He去参加会议)

Our teacher promised to have a good rest.

老师答应(允诺)他要好好休息。

Our teacher promised us to have a good rest.

老师答应我们(老师向我们许下诺言)他要好好休息。

(绝不是让我们好好休息。“Our teacher allowed us to have a good rest.”才是此意)

3.hope to do sth.希望做某事

hope该词只有此句型,而没有hope sb.to do sth.(×)

I hope to do it myself.我希望自己亲自做。

(×)I hope you to do it yourself.

比较

want sb. to do sth.would like sb. to do sth.的意思一样,只不过后者更客气一些。want to do~与would like to do~是一样的,只是语气不同。

I would like you to help me.

我想请你帮忙。

(更客气些)

I want you to help me.

我想要你帮忙。

注意

要表达希望某人做某事,不可用hope作动词,而需要用wantwould like等动词(参见1861.)。

6 tooto/enough to(这是两个非常有用的句型,务必要熟记)

I was too tired to sleep.我太累了,(以致)难于入睡。

He was lucky enough to find a seat.他够幸运的,能找到座位。

1.句型:too +形容词或副词+to do.

太……(以致)不能(做)……

They are too shy to speak English.

他们太腼腆了,说不了英语。

The boy was too frightened to move.

小男孩太害怕了,(以致)一步也动不了。

此句型还可以是toofor sb. / sth. to do.意思是:对于某人(某物)来说,太……以致不能……

The question is too difficult for us to answer.

这问题对我们来讲太难了,我们不能回答。

It is too dark for him to see anything in the room.

房间里太黑了,他什么也看不见。

句型转换

简单句:tooto

复合句:sothatcan't…)

简单句:The box is too heavy for him to lift.

复合句:The box is so heavy that he can't lift it.

这个箱子太沉了,他抬不起来。

简单句:Li Ming was too excited to say a word.

复合句:Li Ming was so excited that he couldn't say a word.

李明太激动了,一句话也说不出来了。

2.句型:形容词+enough to do sth.十分(足够)……

He is rich enough to buy a car.

他很富有,可以买辆小汽车。

他富得足以买辆小汽车。

She was kind enough to help me.

她很善良,才帮助了我。

句型转换

简单句:形容词(副词)+enough +to do

复合句:sothat can do

简单句:He runs fast enough to get there first.

复合句:He runs so fast that he can get there first.

他跑得够快的,完全可以第一个到达。

简单句:The question is simple enough for him to answer.

复合句:The question is so simple that he can answer it.

对于他来讲,这个问题很简单,他可以回答。

7 It iswas+形容词+offorsb. to.

It is kind of you to help me.您能帮助我,真是太好了。

It is easy for me to speak English.对于我来讲,说英语很容易

It iswas+形容词+offorsb.to.》这一句型非常重要,应用也十分广泛,应特别注意offor的使用情况。

在什么情况下用for sb.,什么情况下用of sb.呢?

主要从以下两方面来进行区别:

1.两者所使用的形容词不同

a. for sb.的句型通常使用表示客观情况的形容词

如:easydifficulthardimportantnecessaryunnecessarypossibleimpossibleinteresting等。

It was hard for him to say good-bye.

对他来说,道声再见是很难的。

b. of sb.的句型一般用表示主观感情或态度的形容词。如:goodkindnicewisecleverfoolishrightwrongcarefulcareless等。

It is foolish of you to do that.

你真傻,做那样的事。

It was clever of him to say good-bye.

对于他来说,(在那种时刻)说声再见是最明智不过了。

2.of sb.句型一般都可以转换成一个不定式作状语的句子,而for sb.句型则不可以。

It is very kind of you to help me.

→(○)You are very kind to help me.

你帮助我,真是太好了!

It is right of you to fight for the people.

→(○)You are right to fight for the people.

为人民而斗争是正确的。

It is very important for her to express her opinions.

表达她的意见,对她来讲是非常重要的。

(×)She is very important to express her opinions.