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.
The most importary thing is how to get the jcb.