動詞不定式用法解密

動詞不定式的基本形式是“to+動詞原形“,有時可以不帶to.動詞不定式沒有人稱和數的變化,在句子中不能作謂語。在句中可以作主語、表語、賓語、賓語補足語、定語和狀語。

一、作主語，可以用it代替，it叫形式主語，動詞不定式放在後面叫真正主語

1．To learn a foreign language is not easy. It is not easy to learn a foreign language.

2. It’s dangerous to drive very fast.

二、如果賓語太長，可用it作形式賓語，構成“主語+謂語+ it +賓語不足語(名詞或形容詞) + to do sth”結構，謂語動詞常為find、think、feel等。

I found it difficult to stop him.我發現攔截他很困難。

三、常可接動詞不定式作賓語的動詞有：

agree(同意), hope(希望), decide(決定), need(需要), mean(打算), wish(希望), fail(失敗), want(想要), begin(開始), would like(想要等。Ask(請求）, beg（乞求), leave, like, love, hate(討厭）, prefer（寧願）, order（命令）, teach,（教）tell,（告訴）believe（相信）, find,（找出）know,（知道）want,（想要）think,（認為）understand,（明白）

後面跟動詞不定式的動詞口訣有：

三個希望兩答應（wish hope wantpromis agree)

兩個要求莫拒絕（ask begrefuse )

想要明白跟知道（would likeunderstandknow )

教會告訴要相信（teach tell believe )

找出愛恨區別點（find love hate )

He has decided to go to the countryside.他已決心去鄉下。

四、（1）“疑問詞+動詞不定式”結構可以作動詞know、think、find out等的賓語。I don’t know who to ask.我真不知道該問誰。

（2）“疑問詞+動詞不定式”可以作動詞show、teach、ask等後面的直接賓語。

She told me where to find the earphone.她告訴我什麼地方可以找到耳機。

五、動詞不定式可以作介詞的賓語。

Autumn harvest isaboutto start.秋收即將開始。

I’m worryingaboutwhat to do next.我正愁下一步該怎麼辦。

六、作定語的動詞不定式與被修飾詞有動賓關係。此時，如果動詞不定式的動詞為不及物動詞，後面的介詞絕對不能省略。

動詞分“及物”和“不及物”，“及”你就理解成“涉及，有聯”，“物”你就理解成“事物或人”。及物的動詞”就是“涉及事物的動詞”即“有受對象的動詞”或“帶賓語的動詞”（像買buy,花費spend），“不及物的動詞”就是“不帶賓語的動詞”“沒有動作承受對象的動詞”（像跑run，跳jump,）。所以介詞不能夠省略。

I have a lot of books to read.我有許多書要讀。

We had only a cold room to livein.我們只有寒室一間。

七、不定式複合結構作主語時，需注意：

（1）It’s +形容詞+ for / of + sb + to do sth.

當上面的形容詞指的是to do sth的性質時，用介詞for。

It’s dangerous for children to swim in the river.孩子在這條河裡游泳很危險。（游泳這件事情危險）

（2）當上面的形容詞指的是sb的性質時，用介詞of。

這些形容詞往往修飾人：good, bad, polite, unkind, kind, nice, clever, right, wrong, careful, careless

It was careless of you to do that.你這麼做真粗心。（你這個人粗心）

八、感官動詞hear, see, feel, watch, notice, look at, listen to後面直接跟動詞原形,即常見的形式為: hear sb do sth等

感官動詞後既可跟動詞原形作賓補，也可跟v-ing作賓補，前者表示動作的全部過程已結束；後者表示動作正在進行。

Many people like towatchothersplay games.許多人喜歡看別人玩遊戲.

Isawhimcomedownstairs.我看見他下了樓。（說明他下樓了這件事）

Isawhimcomingdownstairs.我看見他在下樓。（說明他下樓時的情景）

九、使役動詞let, make, have後面直接跟動詞原形; help後面的動詞不定式作賓語補足語, to可有可無

She let us meet her at the station, but she didn’t come.她讓我們去車站迎接她,卡她沒有來.

十、區別下列詞組的不同含義:

remember to do 記住要做某事

remember doing 記得曾經做過某事

forget to do忘記要做某事

forget doing 忘記曾經做過某事

stop to do 停下來去做某事

stop doing 停止做某事

go on to do 繼續做另一件事

go on doing 繼續做原來在做的事

十一、It takes sb some time to do sth.花費某人一段時間幹某事.

It took me half an hour to do my homework yesterday.昨天我花了半小時做回家作業.

It took Jim an hour and a half to read the book.吉姆花了一個半小時看這本書.

It took mother one and a half hours to do the housework.母親花了一個半小時幹家務.

用漢字表述上面的句型為:It + take +人+一段時間+ to do sth.

一段時間形式往往為像這樣的例子:

fifteen minutes15分鐘,an hour一個小時, two days兩天, half a month半個月,a year and a half一年半...等等

十二、不定式的特殊句型Why not

"Why not +動詞原形"表達向某人提出建議，翻譯為："為什麼不……?" "幹嗎不……?"

例如：　Why not take a holiday?幹嗎不去度假?

練習

根據括號內的動詞,用適當的形式填空,空內可能不只填一個詞,使句子完整意思正確

1. They usually __________ kites on Sundays. (fly)

2. Look! The dogs __________ after the cat. (run)

3. Miss Gao __________ English in our school since she came here. (teach)

4. The class meeting _________ last Wednesday afternoon. (hold)

5. You should let him __________ the work by himself. (finish)

6. Meimei __________ to wash the old woman’s clothes twice every week. (go)

7. Mr Jiang __________ us Chinese last term. (teach)

8. My father __________ back from Japan tomorrow. (come)

9. It’s seven o’clock now. The Greens __________ breakfast together. (have)

10. Jim __________ many Chinese songs since he came to China. (learn)

11. Please remember __________ the window when you leave the room. (close)

12. After school some students began to do some __________ in the classroom. (clean)

13. English __________ widely in the whole world today. (speak)