動(dòng)詞不定式的用法小結(jié)

一、構(gòu)成

動(dòng)詞不定式是英語(yǔ)中動(dòng)詞的一種非謂語(yǔ)形式，即由小品詞+動(dòng)詞原形構(gòu)成，有兩種形式，一種是不帶to的不定式，另一種是帶to的不定式。動(dòng)詞不定式（含動(dòng)詞不定式短語(yǔ)）有名詞、形容詞和副詞的作用，在句子中除了不能充當(dāng)謂語(yǔ)之外，可以充當(dāng)其他任何句子成份。（注意：有一類謂語(yǔ)動(dòng)詞后只能接不帶有to的不定式。）

1.使役性動(dòng)詞。如：have、let、make等，例：Qoit stop her let her to home.

2.感官動(dòng)詞。如：see、hear、notice、feel、taste、smell等，例：I heard somebody cry last night.

3.情態(tài)動(dòng)詞。如：can、may、must等。例：You can go first.

4.一些固定結(jié)構(gòu)如。Could、do、nothing、but、had、better、would、rather……than等。例：Youid bctfer ask the teacher first.

5.Why和Why not引導(dǎo)的提建議句型：

Why not go there with me at once？

Why do you come here so early?

6.兩個(gè)不定式被連接在一起時(shí)后不定式省去的：

It’s better to do than (to) say.

二、動(dòng)詞不定式的時(shí)態(tài)和語(yǔ)態(tài)

1.動(dòng)詞不定式一般式的主動(dòng)語(yǔ)態(tài)“to+動(dòng)詞原形”除表示現(xiàn)在情況外，還可以表示將來。例：It’s very nice to see you.

2.動(dòng)詞不定式一般式的被動(dòng)語(yǔ)態(tài)“to be +過去分詞”，例：The old should be treated as a child.

3.動(dòng)詞不定式進(jìn)行時(shí)態(tài)，如：“to be +doing”表示這個(gè)動(dòng)作與句中謂語(yǔ)動(dòng)詞所表示的動(dòng)作同時(shí)發(fā)生。例：He seems to be reading English.

4.動(dòng)詞不定式完成時(shí)態(tài)的被動(dòng)語(yǔ)態(tài)，形式為“to have been+過去分詞，表示這一動(dòng)作發(fā)生在主語(yǔ)動(dòng)作之前。例：She seemed to have unclerstood me.

5.動(dòng)詞不定式的完成式的被動(dòng)語(yǔ)態(tài)形式為“to have been+過去分詞”。例：It was very angry to have been treated as a child.

三、動(dòng)詞不定式的用法

1.作主語(yǔ)時(shí)，常用it作形式主語(yǔ)（it無詞義）而將不定式尾后作真正主語(yǔ)。例：To learn English well is very usefull→It’s very usefull to learn English well. 注意：It’s + adj +for / of + sb + to do sty中當(dāng)形容詞。如：carefull、clever、kind、good、right、wrong等詞時(shí)或當(dāng)sb與形容詞有邏輯上的主謂關(guān)系時(shí)用of。例：It’s kind of you to help me.

2.作賓語(yǔ)、動(dòng)詞不定式常在：want、begin、stait、like、forget、ask、learn、decide、wish、hope、agree、refuse、fail、plan等的物動(dòng)詞后作賓語(yǔ)。例：He asked us to do that thing.

注意：動(dòng)詞不定式作賓語(yǔ)時(shí)，可用形式賓語(yǔ)it代替，不定式后移作真正賓語(yǔ)，其句型結(jié)構(gòu)為：S+V+it+adj+(for sb) to do sth.例：I found it hessong to do that thing.

這類作謂語(yǔ)的動(dòng)詞有：think、make、find、feel等。

3.作表語(yǔ)：多用來表示將來的職業(yè)或要做的某件事。

例：Her job is to help the patients.

The most important thing is to funisb the book.

4.作定語(yǔ)，有兩種情況

(1)被修飾成份在意義上是不定式所表動(dòng)作的執(zhí)行者，不定式的動(dòng)詞可以是積極動(dòng)詞，如果是及物動(dòng)詞就要帶上賓語(yǔ)：He is the first one to come. And the last to leave.I saw him vide abike.

(2)被修飾成份在意義上是不定式的動(dòng)作的承受者時(shí)，不定式的動(dòng)詞應(yīng)是及物動(dòng)詞，如是不及物動(dòng)詞，其后應(yīng)加相應(yīng)的介詞。例：He has no pencit to writle with.

總之，作定語(yǔ)的不定式與所修飾的名詞在意義上有主謂關(guān)系或動(dòng)賓關(guān)系，并且不定式放在被修飾的名詞之后。

5.作狀語(yǔ)

(1)作目的狀語(yǔ)，表示做該動(dòng)作的目的：

He came here to see his father.

(2)作原因狀語(yǔ)：用在某些作表語(yǔ)的表情緒的形容詞之后，說明產(chǎn)生這種情緒的原因，例：I’m sorry to hear that ……

常用的這類形容詞有：sorry、happy、pleased、angry、clever、polite、foolish、wrong、saynised等。

(3)作結(jié)果狀語(yǔ)

①only+不定式用來表示未預(yù)料到或令人沮喪的結(jié)果。例：I hurriecl to his house only to fird he was out.

②形副+enough+不定式，意為“只能……”來表示肯定的結(jié)果：He’s old enorgh to go to school.

③too+形副+不定式“有太……，都不能……”之意，有否定的意思：You ane too yourd to understand this.

④So……as+不定式結(jié)構(gòu)，只表示結(jié)果。

He struck the snake so as to breack it’s back.

⑤有些動(dòng)詞不定式在不及物動(dòng)詞后或在及物動(dòng)詞的賓語(yǔ)后面，可作結(jié)果狀語(yǔ)：They lived have to see the river.

(4)動(dòng)作不定式也可跟在部分作表語(yǔ)的形容詞后作狀語(yǔ)，例：He is easy to get on with.

(5)部分動(dòng)詞后面用不定式和動(dòng)名詞作賓語(yǔ)均可，但意義上有差別，要區(qū)別對(duì)待，這樣的動(dòng)詞有stop、rememhen、forget、help等。

(6)名詞+短語(yǔ)“疑問句+不定式”這種結(jié)構(gòu)，在句子中可以作主語(yǔ)、賓語(yǔ)或表語(yǔ)，相當(dāng)于一個(gè)從句，例：

She asked her mother when to go home.

Her to do the work is easy to decide.

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