1. 現(xiàn)在完成時(shí)的基本結(jié)構(gòu)
肯定句:主語+have/has+動(dòng)詞的過去分詞+其他
否定句:主語+have/has+not+動(dòng)詞的過去分詞+其他
一般疑問句:Have/Has+主語+動(dòng)詞的過去分詞+其他
特殊疑問句:特殊疑問詞+一般疑問句(have/has+主語+過去分詞+其他)
(1)現(xiàn)在完成時(shí)用來表示過去已經(jīng)完成的動(dòng)作對(duì)現(xiàn)在造成影響或后果。也就是說,動(dòng)作或狀態(tài)發(fā)生在過去但它的影響現(xiàn)在還存在,強(qiáng)調(diào)的是現(xiàn)在。
I have already posted the photo.
與此種用法連用的時(shí)間狀語時(shí)一些模糊的過去時(shí)間狀語,如already(肯定句句中), yet(否定句/疑問句句尾), just, before, recently, still, lately, never等。
(2)現(xiàn)在完成時(shí)也可用來表示動(dòng)作或狀態(tài)發(fā)生在過去某一時(shí)刻,持續(xù)到現(xiàn)在并且有可能會(huì)繼續(xù)持續(xù)下去。
He has lived here since 1978.
自從1978年以來,他一直住在這兒。(動(dòng)作起始于1978年,一直住到現(xiàn)在,可能還要繼續(xù)住下去。)
此種用法常與for(+時(shí)間段), since(+時(shí)間點(diǎn)或過去時(shí)的句子)連用。謂語動(dòng)詞必須是延續(xù)性動(dòng)詞。
有些瞬間動(dòng)詞可變?yōu)檠永m(xù)動(dòng)詞:
catch a cold----have a cold
對(duì)于現(xiàn)在完成時(shí)的考查,多以單選、句型轉(zhuǎn)換或詞語運(yùn)用的形式考查學(xué)生在具體語境中靈活運(yùn)用時(shí)態(tài)的能力。在考試中,會(huì)讓大家判斷是否該用現(xiàn)在完成時(shí),或者是考查“瞬間動(dòng)詞”不能與表示一段時(shí)間的狀語連用”這一知識(shí)點(diǎn)。
His father_____the party since 1978
解析:本題考查學(xué)生對(duì)現(xiàn)在完成時(shí)的熟練掌握。since 1978表達(dá)“自從1978年一直到現(xiàn)在”,表示這件事情從過去一直持續(xù)到現(xiàn)在,應(yīng)該用現(xiàn)在完成時(shí),而且動(dòng)詞必須是延續(xù)性動(dòng)詞,A、B均為瞬間動(dòng)詞,不能與時(shí)間段連用,故排除;C為一般過去時(shí),也不行。
4. 比較一般過去時(shí)和現(xiàn)在完成時(shí)的異同
(1)共同點(diǎn):動(dòng)作都是在過去完成。
I saw the film yesterday evening.
I have seen the film before.
①現(xiàn)在完成時(shí)強(qiáng)調(diào)過去發(fā)生的動(dòng)作對(duì)現(xiàn)在的影響和結(jié)果,而一般過去時(shí)與現(xiàn)在沒有聯(lián)系,只是說明某個(gè)動(dòng)作發(fā)生的時(shí)間是在過去。
②一般過去時(shí)通常與具體明確的過去時(shí)間狀語連用。如yesterday, last week, two years ago, just now, in 2002 等;而現(xiàn)在完成時(shí)則常與 just, already, ever, never等模糊的過去時(shí)間狀語和these days, this week, since..., for...等表示一段時(shí)間的狀語連用。
—______ you ______ your homework yet?
—Yes. I ______ it a moment ago .
C. Have; done; have finished
解析:本題考查一般過去時(shí)和現(xiàn)在完成時(shí)的用法區(qū)別。問句中的yet表明應(yīng)該用現(xiàn)在完成時(shí),而回答中的a moment ago是一個(gè)明確的過去時(shí)間狀語,應(yīng)該用一般過去時(shí)。
被動(dòng)語態(tài)由助動(dòng)詞be加及物動(dòng)詞的過去分詞構(gòu)成,助動(dòng)詞be有時(shí)態(tài),人稱和數(shù)的變化。被動(dòng)語態(tài)的時(shí)態(tài)是由be的時(shí)態(tài)決定的,be是什么時(shí)態(tài),全句就是什么時(shí)態(tài),be動(dòng)詞后面的過去分詞不變?! ?/span>
1. 各種時(shí)態(tài)的被動(dòng)語態(tài)結(jié)構(gòu)
一般現(xiàn)在時(shí)的被動(dòng)語態(tài):主語+am/is/are(not)+過去分詞
一般過去時(shí)的被動(dòng)語態(tài):主語+was/were+過去分詞
現(xiàn)在完成時(shí)的被動(dòng)語態(tài):主語+have/has+been+過去分詞
一般將來時(shí)的被動(dòng)語態(tài):主語+will+be+過去分詞
過去將來時(shí)的被動(dòng)語態(tài):主語+would/should+be+過去分詞
過去進(jìn)行時(shí)的被動(dòng)語態(tài):主語+was/were+being+過去分詞
過去完成時(shí)的被動(dòng)語態(tài):主語+had+been+過去分詞
情態(tài)動(dòng)詞的被動(dòng)語態(tài):情態(tài)動(dòng)詞+be+過去分詞
2. 被動(dòng)語態(tài)的用法
(1)不知道或沒有必要說明動(dòng)作的執(zhí)行者是誰,不用by+動(dòng)作執(zhí)行者短語。
Football is played widely all over the world.
全世界都廣泛地踢足球。
(2)強(qiáng)調(diào)動(dòng)作的承受者。
The bank was robbed yesterday afternoon.
昨天下午這家銀行遭到搶劫。
(3)作客觀說明時(shí),常采用一種被動(dòng)語態(tài)句型。
It is reported that about twenty children have died of flu in the USA.
據(jù)報(bào)道美國(guó)大約二十名兒童死于流感。
3. 主動(dòng)語態(tài)的句子變?yōu)楸粍?dòng)語態(tài)的步驟
(1)把原句中的賓語變?yōu)橹髡Z
(2)動(dòng)詞改為被動(dòng)形式,即be+過去分詞
(3)原來的主語,如果需要的話,放在by后面;如果沒必要,可省略。
動(dòng)詞不定式是由“不定式符號(hào)to+動(dòng)詞原形”構(gòu)成的一種非謂語動(dòng)詞結(jié)構(gòu)。有些動(dòng)詞不定式不帶to。
動(dòng)詞不定式可以作句子的主語、表語、賓語、定語、補(bǔ)語、狀語或單獨(dú)使用。
不定式保留動(dòng)詞的某些特性,可以有自己的賓語、狀語等。
動(dòng)詞不定式和它后面的賓語、狀語等一起構(gòu)成短語,叫作不定式短語。
直接把動(dòng)詞不定式置于句首的情況不多,多數(shù)情況用it作形式主語,把真正的主語——動(dòng)詞不定式置于句末,特別是不定式短語較長(zhǎng)時(shí)。
動(dòng)詞不定式作主語,謂語動(dòng)詞用第三人稱單數(shù)形式。
It is our duty to try our best to deal with these problems.
The head teacher said it was necessary to talk with his mother.
How to learn English well is important.
動(dòng)詞不定式作表語,常說明主語的內(nèi)容、性質(zhì)、特征。
The best way is to join an English club.
The first thing is to listen to the teacher carefully.
(1)可以接帶to的動(dòng)詞不定式作賓語的動(dòng)詞主要有:
要求選擇同意(ask, choose, agree)
期望決定學(xué)習(xí)(expect, hope, decide, learn)
寧可假裝知道(prefer, pretend, know)
希望想要愿意(wish, want, would like/love)
We decided to talk to some students about why they go there.
我們決定和一些學(xué)生談?wù)勊麄內(nèi)ツ抢锏脑颉?/span>
He prefers to eat white bread and rice.
(2)動(dòng)詞feel, find, make, think等后面,可以用it作形式賓語代替真正的賓語—動(dòng)詞不定式,句子結(jié)構(gòu)是...feel/find/make/... it+adj./n.+to do....
I find it difficult to remember everything.
(3)既可接動(dòng)詞不定式又可接v-ing形式作賓語,意思差別不太大的動(dòng)詞有begin, start, like, love等。
一般說來,動(dòng)詞不定式表一次、數(shù)次的具體動(dòng)作、將來動(dòng)作或動(dòng)作的全過程,v-ing形式表習(xí)慣性的連續(xù)動(dòng)作。但是這種區(qū)別并不很嚴(yán)格,特別是美國(guó)英語,即使是習(xí)慣性的動(dòng)作也可以用動(dòng)詞不定式。
Then I started to watch TV.
I am beginning to understand my parents.
I like to eat vegetables.
(4)后接動(dòng)詞不定式或v-ing形式作賓語,意思差別較大的動(dòng)詞有forget, remember等。后接不定式作賓語,表動(dòng)作尚未發(fā)生;后接ving形式作賓語,表動(dòng)作已經(jīng)發(fā)生。
stop to do停下來做另外一件事,to do是目的狀語;stop doing停止做、不做當(dāng)前這件事,doing是賓語;
try to do盡力做,try doing試試看;
go on to do接著做另外的事,go on doing繼續(xù)做原來的事。
When I left home, I forgot to bring it with me.
I stopped using them last year.
The question to be discussed next meeting is a difficult one.
下次會(huì)議要討論的這個(gè)問題非常難。
(2)當(dāng)被修飾詞是最高級(jí)或序數(shù)詞或被其修飾時(shí)。
He is always the first man to come to the office.
He is the best man to do the job.
This is the best way to work out the maths problem.
這是解決這道數(shù)學(xué)題最好的辦法。
I have a chance to travel to London.
我又一個(gè)去倫敦旅行的機(jī)會(huì)。
(1)帶to的動(dòng)詞不定式作賓語補(bǔ)足語的動(dòng)詞主要有:
要求允許提議(ask, allow, advise)
期望邀請(qǐng)鼓勵(lì)(expect, invite, encourage)
教導(dǎo)告訴想要(teach, tell, want)
等待希望愿意(wait for, wish, would like/love)
I’d invite her to have dinner at my house.
We should allow the children to choose their own clothes.
(2)動(dòng)詞不定式作補(bǔ)語,在主動(dòng)語態(tài)句里不帶to,被動(dòng)語態(tài)句里帶to時(shí),多數(shù)動(dòng)詞是感官動(dòng)詞和使役動(dòng)詞。
包括四“看”:look at, observe, see, watch;
This picture makes me feel excited!
We saw Liu Yu play baseball last week.
(3)help后接動(dòng)詞不定式作補(bǔ)語,to可帶可不帶。
They can help you (to) learn English.
(1)目的狀語,置于句首或句末,置于句首時(shí)常表示強(qiáng)調(diào)。
In order to catch the early bus, she got up very early.
A group of young people got together to discuss this question.
She came to this city to visit her daughter.
(2)原因狀語,多見于“sb.+be+adj.+to do...”結(jié)構(gòu)句中。
I feel very lucky to have him.
(3)結(jié)果狀語,多見于“too...to”,“enough to...”結(jié)構(gòu)句中。
I’m too tired to do it well.
The room is big enough for three people to live in.
7. 動(dòng)詞不定式的復(fù)合結(jié)構(gòu)
動(dòng)詞不定式的復(fù)合結(jié)構(gòu)是“for/of sb. to do sth.”。
不定式復(fù)合結(jié)構(gòu)的介詞用for還是of,主要決定于前面形容詞的性質(zhì)。
一般說來,of前面的形容詞是careful, clever, foolish, good,kind, nice, wise等,說明人的特性。
for前面的形容詞是dangerous,difficult, easy, hard, heavy, important, interesting, necessary等,一般說明不定式動(dòng)作的特性,前面如果是名詞用for。
It’s a good idea for parents to allow children to study in groups during the evening.
對(duì)父母來說,在晚上讓孩子分組學(xué)習(xí)是個(gè)好主意。
It’swise of him to do it well.
動(dòng)詞不定式前面可以帶疑問代詞what, which, who或疑問副詞how, when, where, why等。
這種結(jié)構(gòu)起名詞的作用,在句子里用作賓語、主語、表語等,或者單獨(dú)使用。要注意的是,why后面的不定式不帶to。
I don’t know what to try next.(作賓語)
Where to go is not decided yet.(作主語)
(2)單獨(dú)使用時(shí)相當(dāng)于一個(gè)特殊疑問句。
Whatto do next?=What will we / you do next?
Whygo there?=Why do we / you go there?
不定式的否定式是not/never to do...;不帶to的不定式的否定式是not/never do...
They decide not to talk to each other.
Hisparents tell him never to play soccer in the street.
動(dòng)名詞相當(dāng)于名詞,在句子中可以做主語、賓語、表語、定語等。
1. 作主語
Fighting broke out between the South and the North.
南方與北方開戰(zhàn)了。
2. 作賓語
Would you mind turning down your radio a little, please?
請(qǐng)問你介意調(diào)小一點(diǎn)收音機(jī)的音量嗎?
3. 作表語
Babysister’s job is washing,cooking and taking care of the children.
保姆的工作是洗衣、做飯和照看孩子。
4. 做定語
a washing machine 一臺(tái)洗衣機(jī)。
Some are singing and dancing under a big tree. Some are drawing by the lake.
Your son will be all right by supper time.
How many English songs had you learned by the end of last term?
到上個(gè)學(xué)期末你們已經(jīng)學(xué)了多少首英語歌曲?
3. 表示方法、手段,可譯作“靠”、“用”、“憑借”、“通過”、“乘坐”等
The monkey was hanging from the tree by his tail and laughing.
The boy’s father was so thankful that he taught Edison how to send messages by railway telegraph.
孩子的父親是那么的感激,于是他教愛迪生怎樣通過鐵路電報(bào)來傳達(dá)信息。
One by one they went past the table in the dark.
他們一個(gè)一個(gè)得在黑暗中經(jīng)過這張桌子。
What time is it by your watch?
6. 和take, hold等動(dòng)詞連用,說明接觸身體的某一部分
7. 用于被動(dòng)句中,表示行為主體,常譯作“被”、“由”等
English is spoken by many people.
1. 肯定句:used這個(gè)詞沒有人稱的變化,to后面接動(dòng)詞原形。
When I was a child, I didn’t use to like apples.
當(dāng)我還是孩子的時(shí)候我不喜歡蘋果。
Where did you use to live before you came here?
2. 含有used to的句子的反意疑問句不要usedn’t+主語,而用didn’t+主語。
——He used to smoke, didn’t he?
Yes, he did./No, he didn’t.
如果我們所說的不是事實(shí),而只是一種假設(shè)、愿望、建議或是一種實(shí)現(xiàn)不了的空想就用虛擬語氣。
注意:條件句分兩種,真實(shí)條件句和虛擬條件句。只有在虛擬(非真實(shí))條件句中,才用虛擬語氣;而在真實(shí)條件句中,要用陳述語氣。
(1)If it is sunny tomorrow , we’ll go to the zoo.
在這句話中,明天天氣好是完全有可能實(shí)現(xiàn)的,并非虛擬、幻想,因此是真實(shí)條件句,在本句中,適用“主將從現(xiàn)。”
(2)If I were you, I would go at once.
在這句話中,條件句“如果我是你”,但事實(shí)上,我不可能成為你,這只是假設(shè)的情況,沒有實(shí)現(xiàn)的可能。當(dāng)條件實(shí)現(xiàn)的可能性很小,甚至可以說沒有時(shí),就需要用虛擬語氣來表示。
虛擬語氣表示和現(xiàn)在的事實(shí)相反,從句用一般過時(shí),主句用“should/would/could/ might+動(dòng)詞原形。
If I had time, I would go for a walk.
If I were invited, I would go to the dinner party.
If I won a million dollars in the lottery, I would put it in the bank.
If I were you, I’d wear a shirt and tie.
注意:在虛擬語氣的句子中,be動(dòng)詞只能用were,不能用was。
You must stay here until I come back.
Must I hand in my homework right now?
對(duì)must引導(dǎo)的疑問句,肯定回答為must,否定回答為needn’t 或don’t have to .
—Must I finish my homework?
(2)must也可以表示有把握的推測(cè),意為“ 一定,肯定”,用于肯定句。
The light is on, so he must be at home now.
You mustn’t play with fire.
(1)can的過去式,意為“能、會(huì)”,表示過去的能力。
He could write poems when he was 10.
(2)could在疑問句中,表示委婉請(qǐng)求的語氣,此時(shí)could沒有過去式的意思。
Could you do me a favour?
might為may的過去式。might表示推測(cè)時(shí),表示可能性低于may(此時(shí)might沒有過去式的意思),當(dāng)請(qǐng)求講時(shí),比may的語氣更委婉。
He is away from school. He might be sick.
Might I use your dictionary?
(1)表示能力,一般譯為“能、會(huì)”,尤其指生來具備的能力。
She can swim fast, but I can’t .
You can use my dictionary.
(3)表示推測(cè),意為“可能”,常用于否定句和疑問句中,此時(shí)can’t譯為“不可能”。
—No, it can’t be our teacher. He is on a visit to the Great Wall.