動詞不定式考點透視

徐 峰

一、作主語

動詞不定式作主語時,句子的謂語動詞常用單數(shù),其位置有以下兩種:

(1)把不定式置于句首。如:

To act like that is foolish.

這樣做是愚蠢的。

(2)用it作形式主語,把真正的主語不定式置于句后,常用于下列句式中。如:

①It+be+名詞+to do

lts notan easy thing to master a language.

學好一種語言是不容易的。

②It takes sb + some time + to do

How long did it take you to finish the work?

你花了多少時間完成這項工作?

③It + be + 形容詞+ for sb + to do

It is not hard for one to do a bit of good.

一個人做點好事并不難。

④It + be +形容詞+ of sb + to do

It is kind of you to think so much of us.

難為你這樣替我們想。

⑤It seems (appears) +形容詞+ to do

It seems a pity to refuse.

拒絕似乎是很遺憾的。

二、作賓語

不定式用作賓語的時候特別多,主要有以下兩種情況:

(1)動詞+不定式

afford,aim,appear,agree,arrange,ask,be,decide,bother,care,choose,come,dare,demand,expect,elect,hope,fail,happen,help,learn,long,mean,manage,offer,ought,plan,prepare,pretend,promise,refuse,seem,tend,wait,wish,undertake.如:

They preferred not to put this on the agenda.

他們寧愿不把這列入議程。

He demanded to know what I had been doing.

他要求知道我一直在干什么。

(2)動詞+不定式;動詞+賓語+不定式

ask, beg, choose, expect,hate,help intend like,love,need prefer,prepare,promise,want,wish.

I like to keep everything tidy.

我喜歡每件東西都保持整潔。

I like you to keep everything tidy.

我喜歡你使每件東西都保持整潔。

(3)動詞+疑問詞+to

decide, know, consider forget, learn, rememb- er, show, understand, see, wonder, hear,find out, explain, tell.

Please show us how to do that.

請演示給我們如何去做。

There are so many kinds of tape-recorders on sale that I cant make up my mind which to buy.

有這么多的錄音機,我都拿不定主意買哪

一種。

注意:疑問詞帶不定式在句中作成分時,謂語動詞用單數(shù)。

I hardly know what to say before you.

我?guī)缀醪恢涝谀忝媲霸撊绾握f。

(4)以下動詞后,只能跟不定式作賓語。如:

agree, ask, aim, arrange, choose, decide, demand, expect, help, hope, fail, long, manage, offer, plan, prepare, pretend, refuse, wish等,這些詞大部分可接that引導的從句。如:

He decided to finish the work in three days.

他決定三天內完成這項工作。

She pretended to be listening to the teacher carefully.

她假裝正在認真聽講。

Do you wish to see the manager?

你想見經(jīng)理嗎?

He likes to have a good meal.

他喜歡中午吃一頓好飯。

(5)當復合賓語中的賓語是不定式時,先用形式賓語it代替不定式,把不定式置于補語之后,即:主語+動詞+it+補語+to do句式。如:

We think it quite important for us to learn a foreign language well.

我們認為學好一門外語對我們來說是相當重要的。

He feels it his duty to help the poor.

他覺得幫助窮人是他的職責。

三、作補語

有很多動詞的后面都可以有不定式做賓語補足語,常見的情況為:

(1)動詞+賓語+不定式(to do)

advise,allow,believe,cause,consider,drive, enable,encourage,find,guess,imagine,invite,know,like,order,remind,report,require,send,state,suppose,tell,think,train,trust,understand,warn.如:

He wanted me to call him when I go there.

他想讓我到那兒時給他打電話。

What decided him to give up his job?

是什么決定他放棄工作的?

(2)to + be的不定式結構,作補語的動詞

acknowledge,believe,consider,think,discover,feel,find,guess,judge,imagine,know,prove,see(理解),show,suppose,take(以為),understand.如:

We consider Tom to be one of the best students in our class.

我們認為湯姆是班上最好的學生之一。

(3)to be +形容詞

seem,appear,be said,be supposed,be believed,be thought,be known,be reported,hope,wish,desire,want,plan,expect,mean.如:

The book is believed to be uninteresting.

人們認為這本書沒什么意思。

(4)there be +不定式

believe,expect,intend,like,love,mean,prefer,want,wish,understand.如:

We didnt expect there to be so many people there. 我們沒料到會有那么多人在哪里。

四、作表語

不定式作表語表示具體動作或將來動作;動名詞作表語表示抽象的一般行為。

①To be kind to the enemy is to be cruel to the people.

②My chief purpose is to point out the difficulties of the matter.

③What I would suggest is to put off the meeting.

當主語和表語都是不定式時,其含義一是條件,一是結果(例①)。當主語是aim,duty,hope,idea,mistake,plan,purpose,suggestion等為中心詞的名詞詞組(例②)時,或以what引導的名詞性分句(例③),不定式說明主語的內容。

④Our work is serving the people.

⑤What he likes is taking a walk after supper.

⑥The story told by Mr.Wang is interesting.

④⑤句動名詞作表語,與主語部分可以轉換,如Serving the people is our work,而⑥句中是現(xiàn)在分詞作表語,說明主語的性質、狀態(tài),現(xiàn)在分詞具有形容詞的各種特征,另外,動名詞作表語還應與進行時態(tài)區(qū)別開來。

五、作狀語

動詞不定式常可用作狀語,修飾動詞,表示行為的目的、結果、原因等。一般放在被修飾詞之后,但在表示目的時,為了強調也可放在句首。

(1)目的狀語。

To...only to(僅僅為了),in order to,so as to,so(such)...as to...(如此……以便……)

He ran so fast as to catch the first bus.

他飛快地跑以便趕上第一班車。

I come here only to say good-bye to you.

我來僅僅是向你告別。

(2)作結果狀語,表事先沒有預料到的,要放在句子后面。

Bell went away only to leave his two children by themselves.

貝爾走了,結果只留下兩個孩子。

(3)作原因狀語,往往跟在表示“高興、愉快、生氣、榮耀、遺憾”等含義的形容詞之后,說明產(chǎn)生“高興、愉快、生氣、榮耀、遺憾”等情緒的原因。

Im pleased to be invited to talk here.

我很高興被邀請在這里講話。

六、作定語

不定式在句中作定語,置于被修飾的名詞或代詞之后。如:

①The next train to arrive is from Was- hington.

②Have you anything to be taken to your sister?

③Do you have anything to say on the question?