高三英語(yǔ)語(yǔ)法專(zhuān)題復(fù)習(xí)與訓(xùn)練各類(lèi)從句及連詞

1、高三英語(yǔ)復(fù)習(xí)與訓(xùn)練十七、十八、十九、二十一名詞性從句、定語(yǔ)從句、狀語(yǔ)從句 、連詞17. 名詞性從句 在句子中起名詞作用的句子叫名詞從句。名詞從句的功能相當(dāng)于名詞詞組, 它在復(fù)合句中能擔(dān)任主語(yǔ)、賓語(yǔ)、表語(yǔ)、同位語(yǔ)、介詞賓語(yǔ)等，因此根據(jù)它在句中不同的語(yǔ)法功能，名詞從句又可分別稱(chēng)為主語(yǔ)從句、賓語(yǔ)從句、表語(yǔ)從句和同位語(yǔ)從句。 17.1 引導(dǎo)名詞性從句的連接詞引導(dǎo)名詞性從句的連接詞可分為三類(lèi)： 連接詞： that, whether ,if （不充當(dāng)從句的任何成分） 連接代詞：what, whatever, who, whoever, whom, whose, which 連接副詞：when,

2、where, how, why 不可省略的連詞：1. 介詞后的連詞2. 引導(dǎo)主語(yǔ)從句和同位語(yǔ)從句的連詞不可省略。例如：That she was chosen made us very happy. 她被選上了，我們很高興。We heard the news that our team had won. 我們聽(tīng)到消息說(shuō)我們隊(duì)贏了。 比較：whether與if 均為"是否"的意思。 但在下列情況下，whether 不能被if 取代： 1. whether引導(dǎo)主語(yǔ)從句并在句首 2. 引導(dǎo)表語(yǔ)從句 3. whether從句作介詞賓語(yǔ) 4. 從句后有"or not"

3、; 大部分連接詞引導(dǎo)的主語(yǔ)從句都可以置于句末，用 it充當(dāng)形式主語(yǔ)。例如： It is not important who will go. 誰(shuí)去，這不重要。 It is still unknown which team will win the match. 到底誰(shuí)贏呢，形勢(shì)尚不明朗。 17.2 名詞性that-從句 1）由從屬連詞that引導(dǎo)的從句叫做名詞性that-從句。That只起連接主句和從句的作用，在從句中不擔(dān)任任何成分，本身也沒(méi)有詞義。名詞性that-從句在句中能充當(dāng)主語(yǔ)、賓語(yǔ)、表語(yǔ)、同位語(yǔ)和形容詞賓語(yǔ)。例如： 主語(yǔ)：That he is still alive is sheer

4、 luck. 他還活著全靠運(yùn)氣。 賓語(yǔ)：John said that he was leaving for London on Wednesday.約翰說(shuō)他星期三要到倫敦去。 表語(yǔ)：The fact is that he has not been seen recently. 事實(shí)是近來(lái)誰(shuí)也沒(méi)有見(jiàn)過(guò)他。同位語(yǔ)：The fact that he has not been seen recently disturbs everyone in his office. 近來(lái)誰(shuí)也沒(méi)有見(jiàn)過(guò)他，這一情況令辦公室所有的人不安。 形容詞賓語(yǔ)：I am glad that you are satisfied wi

5、th your job. 你對(duì)工作滿(mǎn)意我感到很高興。 2）That-從句作主語(yǔ)通常用it作先行詞，而將that-從句置于句末。例如： It is quite clear that the whole project is doomed to failure.很清楚，整個(gè)計(jì)劃注定要失敗。 It's a pity that you should have to leave.你非走不可真是件憾事。 用it作形式主語(yǔ)的that-從句有以下四種不同的搭配關(guān)系： a. It + be +形容詞+ that-從句It is necessary that 有必要It is important that

6、 重要的是It is obvious that 很明顯 b. It + be + -ed 分詞+ that-從句It is believed that人們相信It is known to all that 從所周知It has been decided that 已決定 c. It + be +名詞+ that-從句It is common knowledge that 是常識(shí)It is a surprise that 令人驚奇的是It is a fact that 事實(shí)是 d. It +不及物動(dòng)詞+ that-分句It appears that似乎It happens that碰巧It oc

7、curred to me that 我突然想起 17.3 名詞性wh-從句 1）由wh-詞引導(dǎo)的名詞從句叫做名詞性wh-從句。Wh-詞包括who, whom,. whose, whoever, what, whatever, which, whichever等連接代詞和where, when, how, why等連接副詞。Wh-從句的語(yǔ)法功能除了和that-從句一樣外，還可充當(dāng)介詞賓語(yǔ)、賓語(yǔ)補(bǔ)語(yǔ)和間接賓語(yǔ)等。例如：主語(yǔ)： How the book will sell depends on its author.書(shū)銷(xiāo)售如何取決于作者本人。直接賓語(yǔ)：In one's own home on

8、e can do what one likes.在自己家里可以隨心所欲。間接賓語(yǔ)：The club will give whoever wins a prize.獲勝者俱樂(lè)部將頒獎(jiǎng)。表語(yǔ)： My question is who will take over president of the Foundation.我的問(wèn)題是誰(shuí)將接任該基金會(huì)主席職位。賓語(yǔ)補(bǔ)足語(yǔ)：She will name him whatever she wants to. 她高興給他起什么名字就取什么名字。同位語(yǔ)：I have no idea when he will return. 我不知道他什么時(shí)候回來(lái)。形容詞賓語(yǔ)：I&#

9、39;m not sure why she refused their invitation. 我尚不能肯定她為什么拒絕他們的邀請(qǐng)。介詞賓語(yǔ)：That depends on where we shall go. 那取決于我們?nèi)ツ膬骸?）Wh-從句作主語(yǔ)也常用先行詞it做形式主語(yǔ)，而將wh-從句置于句末。例如：It is not yet decided who will do that job. 還沒(méi)決定誰(shuí)做這項(xiàng)工作。It remains unknown when they are going to get married. 他們何時(shí)結(jié)婚依然不明。17.4 if, whether引導(dǎo)的名詞從句

10、1）yes-no型疑問(wèn)從句從屬連詞if, whether引導(dǎo)的名詞從句是由一般疑問(wèn)句或選擇疑問(wèn)轉(zhuǎn)化而來(lái)的，因此也分別被稱(chēng)為yes-no型疑問(wèn)句從句和選擇型疑問(wèn)從句，其功能和wh-從句的功能相同。例如： 主語(yǔ)：Whether the plan is feasible remains to be proved. 這一計(jì)劃是否可行還有等證實(shí)。 賓語(yǔ)：Let us know whether / if you can finish the article before Friday. 請(qǐng)讓我們知道你是否能在星期五以前把文章寫(xiě)完。 表語(yǔ)：The point is whether we should len

11、d him the money. 問(wèn)題在于我們是否應(yīng)該借錢(qián)給他。 同位語(yǔ)：They are investigating the question whether the man is trustworthy.他們調(diào)查他是否值得信賴(lài)。 形容詞賓語(yǔ)： She's doubtful whether we shall be able to come. 她懷疑我們是否能夠前來(lái)。 介詞賓語(yǔ)： I worry about whether he can pass through the crisis of his illness. 我擔(dān)心他是否能度過(guò)疾病的危險(xiǎn)期。2）選擇性疑問(wèn)從句 選擇性疑問(wèn)從句由關(guān)

12、聯(lián)詞if/whetheror或whetheor not構(gòu)成。例如： Please tell me whether / if they are Swedish or Danish. 請(qǐng)告訴我他們是瑞典人還是丹麥人。 I don't care whether you like the plan or not. 我不在乎你是否喜歡該計(jì)劃。 17.5 否定轉(zhuǎn)移 1）將think, believe, suppose, expect, fancy, imagine等動(dòng)詞后面賓語(yǔ)從句的否定詞轉(zhuǎn)移到主句中，即主句的謂語(yǔ)動(dòng)詞用否定式，而從句的謂語(yǔ)動(dòng)詞用肯定式。例如： I don't think

13、I know you.我想我并不認(rèn)識(shí)你。 I don' t believe he will come.我相信他不回來(lái)。注意：若謂語(yǔ)動(dòng)詞為hope,賓語(yǔ)從句中的否定詞不能轉(zhuǎn)移。例如： I hope you weren't ill. 我想你沒(méi)有生病吧。2）將seem, appear 等后的從句的否定轉(zhuǎn)移到前面。例如： It doesn't seem that they know where to go. 看來(lái)他們不知道往哪去。 It doesn't appear that we'll have a sunny day tomorrow. 看來(lái)我們明天不會(huì)碰上

14、好天氣。3）有時(shí)將動(dòng)名詞，介詞短語(yǔ)或整個(gè)從句的否定轉(zhuǎn)變?yōu)閷?duì)謂語(yǔ)動(dòng)詞的否定。例如： I don't remember having ever seen such a man.我記得從未見(jiàn)過(guò)這樣一個(gè)人。（not否定動(dòng)名詞短語(yǔ) having） It's not a place where anyone would expect to see strange characters on the street. 在這里，人們不會(huì)想到在街上會(huì)碰上陌生的人。（anyone 作主語(yǔ)，從句中的謂語(yǔ)動(dòng)詞不能用否定形式。）4）有時(shí)狀語(yǔ)或狀語(yǔ)從句中否定可以轉(zhuǎn)移到謂語(yǔ)動(dòng)詞前。例如： The ant is

15、 not gathering this for itself alone.（否定狀語(yǔ)）螞蟻不只是為自己采食。 He was not ready to believe something just because Aristotle said so. （否定because狀語(yǔ)） 他并不因亞里斯多德說(shuō)過(guò)如何如何，就輕信此事。 She had not been married many weeks when that man's younger brother saw her and was struckby her beauty.（否定狀語(yǔ)many weeks）她結(jié)婚還不到幾個(gè)月，這個(gè)人的

16、弟弟就看見(jiàn)她了，并對(duì)她的美貌著了迷。 18. 定語(yǔ)從句 定語(yǔ)從句在句中做定語(yǔ)，修飾一個(gè)名詞或代詞，被修飾的名詞詞組或代詞即先行詞。定語(yǔ)從句通常出現(xiàn)在先行詞之后，由關(guān)系詞（關(guān)系代詞或關(guān)系副詞）引出。關(guān)系代詞有：who, whom, whose, that, which等。關(guān)系副詞有：when, where, why等。 18.1 關(guān)系代詞引導(dǎo)的定語(yǔ)從句 關(guān)系代詞所代替的先行詞是人或物的名詞或代詞，并在句中充當(dāng)主語(yǔ)、賓語(yǔ)、定語(yǔ)等成分。關(guān)系代詞在定語(yǔ)從句中作主語(yǔ)時(shí)，從句謂語(yǔ)動(dòng)詞的人稱(chēng)和數(shù)要和先行詞保持一致。1）who, whom, that 這些詞代替的先行詞是人的名詞或代詞，在

17、從句中作主語(yǔ)和賓語(yǔ)。例如： Is he the man who/that wants to see you? 他就是你想見(jiàn)的人嗎？（who/that在從句中作主語(yǔ)） He is the man whom/ that I saw yesterday. 他就是我昨天見(jiàn)的那個(gè)人。（whom/that在從句中作賓語(yǔ)）2） whose 用來(lái)指人或物，（只用作定語(yǔ), 若指物，它還可以同of which互換）。例如： They rushed over to help the man whose car had broken down.那人車(chē)壞了，大家都跑過(guò)去幫忙。 Please pass me the bo

18、ok whose （of which） cover is green.請(qǐng)遞給我那本綠皮的書(shū)。3）which, that所代替的先行詞是事物的名詞或代詞，在從句中可作主語(yǔ)、賓語(yǔ)等。例如：A prosperity which / that had never been seen before appears in the countryside. 農(nóng)村出現(xiàn)了前所未有的繁榮。（which / that在句中作賓語(yǔ)）The package （which / that）you are carrying is about to come unwrapped. 你拿的包快散了。（which / that在句

19、中作賓語(yǔ)）18.2 關(guān)系副詞引導(dǎo)的定語(yǔ)從句 關(guān)系副詞可代替的先行詞是時(shí)間、地點(diǎn)或理由的名詞，在從句中作狀語(yǔ)。1）關(guān)系副詞when, where, why的含義相當(dāng)于"介詞+ which"結(jié)構(gòu)，因此常常和"介詞+ which"結(jié)構(gòu)交替使用。例如： There are occasions when （on which） one must yield.任何人都有不得不屈服的時(shí)候。 Beijing is the place where（in which） I was born.北京是我的出生地。 Is this the reason why （for which

20、） he refused our offer?這就是他拒絕我們幫助他的理由嗎？2）that代替關(guān)系副詞，可以用于表示時(shí)間、地點(diǎn)、方式、理由的名詞后取代when, where, why和"介+which"引導(dǎo)的定語(yǔ)從句，在口語(yǔ)中that常被省略。例如： His father died the year （that / when / in which） he was born.他父親在他出生那年逝世了。 He is unlikely to find the place （that / where / in which） he lived forty years ago. 他不大

21、可能找到他四十年前居住過(guò)的地方。 18.3 判斷關(guān)系代詞與關(guān)系副詞 方法一： 用關(guān)系代詞，還是關(guān)系副詞完全取決于從句中的謂語(yǔ)動(dòng)詞。及物動(dòng)詞后面無(wú)賓語(yǔ)，就必須要求用關(guān)系代詞；而不及物動(dòng)詞則要求用關(guān)系副詞。例如： This is the mountain village where I stayed last year. 這是我去年呆過(guò)的山村。 I'll never forget the days when I worked together with you.我永遠(yuǎn)不會(huì)忘記與你共事的日子。 判斷改錯(cuò)： （錯(cuò)） This is the mountain village where I vi

22、sited last year. （錯(cuò)） I will never forget the days when I spent in the countryside. （對(duì)） This is the mountain village （which） I visited last year. （對(duì)） I'll never forget the days （which） I spent in the countryside.習(xí)慣上總把表地點(diǎn)或時(shí)間的名詞與關(guān)系副詞 where, when聯(lián)系在一起。此兩題錯(cuò)在關(guān)系詞的誤用上。 方法二： 準(zhǔn)確判斷先行詞在定語(yǔ)從句中的成分（主、謂、賓、定、狀），也

23、能正確選擇出關(guān)系代詞/關(guān)系副詞。例1. Is this museum _ you visited a few days age? A. whereB. that C. on which D. the one例2. Is this the museum _ the exhibition was held. A. whereB. that C. on whichD. the one答案：例1 D，例2 A例1變?yōu)榭隙ň洌?This museum is _ you visited a few days ago.例2變?yōu)榭隙ň洌?This is the museum _ the exhibition

24、was held. 在句1中，所缺部分為賓語(yǔ)，而where, that, on which都不能起到賓語(yǔ)的作用，只有the one既做了主句的表語(yǔ)，又可做從句的賓語(yǔ)，可以省略關(guān)系代詞，所以應(yīng)選D。 而句2中, 主、謂、賓俱全，從句部分為句子的狀語(yǔ)表地點(diǎn)，既可用副詞where，又因 in the museum詞組，可用介詞in + which 引導(dǎo)地點(diǎn)狀語(yǔ)。而此題中，介詞on 用的不對(duì)，所以選A。關(guān)系詞的選擇依據(jù)在從句中所做的成分，先行詞在從句中做主、定、賓語(yǔ)時(shí)，選擇關(guān)系代詞（who, whom, that, which, whose）； 先行詞在從句中做狀語(yǔ)時(shí)，應(yīng)選擇關(guān)系副詞 （ where

25、地點(diǎn)狀語(yǔ)，when 時(shí)間狀語(yǔ)，why 原因狀語(yǔ)） 。 18.4 限制性和非限制性定語(yǔ)從句 1） 定語(yǔ)從句有限制性和非限制性?xún)煞N。限制性定語(yǔ)從句是先行詞不可缺少的部分，去掉它主句意思往往不明確；非限制性定語(yǔ)從句是先行詞的附加說(shuō)明，去掉了也不會(huì)影響主句的意思，它與主句之間通常用逗號(hào)分開(kāi)。例如：This is the house which we bought last month. 這是我們上個(gè)月買(mǎi)的那幢房子。（限制性）The house, which we bought last month, is very nice.這幢房子很漂亮，是我們上個(gè)月買(mǎi)的。（非限制性）2） 當(dāng)先行詞是專(zhuān)有名詞或物主

26、代詞和指示代詞所修飾時(shí)，其后的定語(yǔ)從句通常是非限制性的。例如：Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了，他曾經(jīng)是我的老師。My house, which I bought last year, has got a lovely garden.我去年買(mǎi)的的那幢房子帶著個(gè)漂亮的花園。This novel, which I have read three times, is very touching. 這本小說(shuō)很動(dòng)人，我已經(jīng)讀了三遍。3） 非限制性定語(yǔ)從句還能將整個(gè)主句作為先行詞, 對(duì)

27、其進(jìn)行修飾, 這時(shí)從句謂語(yǔ)動(dòng)詞要用第三人稱(chēng)單數(shù)。例如：He seems not to have grasped what I meant, which greatly upsets me. 他似乎沒(méi)抓住我的意思，這使我心煩。Liquid water changes to vapor, which is called evaporation. 液態(tài)水變?yōu)檎羝?，這就叫做蒸發(fā)。說(shuō)明：關(guān)系代詞that和關(guān)系副詞why不能引導(dǎo)非限制性定語(yǔ)從句。 18.5 介詞+關(guān)系詞 1）介詞后面的關(guān)系詞不能省略。2）that前不能有介詞。3）某些在從句中充當(dāng)時(shí)間，地點(diǎn)或原因狀語(yǔ)的"介詞+關(guān)系詞"結(jié)

28、構(gòu)可以同關(guān)系副詞when 和where 互換。例如： This is the house in which I lived two years ago. 這是我兩年前住過(guò)的房子。 This is the house where I lived two years ago. Do you remember the day on which you joined our club? 還記得你加入我們俱樂(lè)部的那一天嗎？ Do you remember the day when you joined our club? 18.6 as, which 非限定性定語(yǔ)從句 由as, which 引導(dǎo)的非限定

29、性定語(yǔ)從句，as和which可代整個(gè)主句，相當(dāng)于and this或and that。As一般放在句首，which在句中。例如：As we know, smoking is harmful to one's health. 如我們所知，吸煙有害健康。The sun heats the earth, which is very important to us. 太陽(yáng)使地球暖起來(lái)，這對(duì)我們?nèi)祟?lèi)很重要。典型例題1）Alice received an invitation from her boss, _came as a surprise.A. it B. that C. whichD. he

30、 答案C. 此為非限定性從句，不能用 that修飾，而用which.，it 和he 都使后句成為句子，兩個(gè)獨(dú)立的句子不能單以逗號(hào)連接。況且選he句意不通。2）The weather turned out to be very good, _ was more than we could expect. A. whatB. whichC. thatD. it 答案B。which可代替句子，用于非限定性定語(yǔ)從句，而what不可。That 不能用于非限定性定語(yǔ)從句，it不為連詞，使由逗號(hào)連接的兩個(gè)句子并在一起在英語(yǔ)語(yǔ)法上行不通。3）It rained hard yesterday, _ preven

31、ted me from going to the park.A. thatB. whichC. as D. it 答案B. as 和which在引導(dǎo)非限制性定語(yǔ)從句時(shí)，這兩個(gè)關(guān)系代詞都指主句所表達(dá)的整個(gè)意思，且在定語(yǔ)從句中都可以作主語(yǔ)和賓語(yǔ)。但不同之處主要有兩點(diǎn)：（1）as 引導(dǎo)的定語(yǔ)從句可置于句首，而which不可。（2） as 代表前面的整個(gè)主句并在從句中作主語(yǔ)時(shí)，從句中的謂語(yǔ)必須是系動(dòng)詞；若為行為動(dòng)詞，則從句中的關(guān)系代詞只能用which.。在本題中，prevent由于是行為動(dòng)詞，所以正確選項(xiàng)應(yīng)為B。as 的用法例1. the sameas；suchas 中的as 是一種固定結(jié)構(gòu), 和一樣

32、。例如： I have got into the same trouble as he （has）. 我碰到了跟他一樣的麻煩。例2. as可引導(dǎo)非限制性從句，常帶有'正如'。例如： As we know, smoking is harmful to one's health. 如我們所知，吸煙有害健康。 As is known, smoking is harmful to one's health. As是關(guān)系代詞。例1中的as作know的賓語(yǔ)；例2中，它充當(dāng)從句的主語(yǔ)，謂語(yǔ)動(dòng)詞know要用被動(dòng)式。 18.7 先行詞和關(guān)系詞二合一 1） Whoever spit

33、s in public will be punished here. （Whoever 可以用 anyone who 代替）2） The parents will use what they have to send their son to technical school.（what 可以用all that代替） 18.8 what/whatever; that/what; who/whoever 1）what = the thing which；whatever = anything。例如：What you want has been sent here. 你要的動(dòng)詞都送來(lái)了。Whate

34、ver you want makes no difference to me. 不管你要什么，跟我沒(méi)什么關(guān)系。2） who= the person that whoever= anyone who。例如： （錯(cuò)）Who breaks the law will be punished. （錯(cuò)）Whoever robbed the bank is not clear. （對(duì)）Whoever breaks the law will be punished. 王子犯法，與庶民同罪。 （對(duì)）Who robbed the bank is not clear. 誰(shuí)搶了銀行還不清楚。3） that 和 wha

35、t 當(dāng)that引導(dǎo)定語(yǔ)從句時(shí)，通常用作關(guān)系代詞，而引導(dǎo)名詞性從句時(shí)，是個(gè)不充當(dāng)任何成分的連接詞。賓語(yǔ)從句和表語(yǔ)從句中的that?？墒÷浴hat只能引導(dǎo)名詞性從句，用作連接代詞，作從句的具體成分，且不能省略。例如：I think（that）you will like the stamps. 我想你會(huì)喜歡這些郵票的。What we need is more practice. 我們需要的是更多的實(shí)踐。18.9 關(guān)系代詞that 的用法 1）不用that的情況 a） 引導(dǎo)非限定性定語(yǔ)從句時(shí)。例如： （錯(cuò)）The tree, that is four hundred years old, is ve

36、ry famous here. b） 介詞后不能用。例如： We depend on the land from which we get our food. 我們依賴(lài)土地獲得食物。 We depend on the land that/which we get our food from.2） 只能用that作為定語(yǔ)從句的關(guān)系代詞的情況 a）在there be 句型中，只用that，不用which。 b）在不定代詞，如：anything, nothing, the one, all, much, few, any, little等作先行詞時(shí)，只用that，不用which。 c）先行詞有the

37、 only, the very修飾時(shí)，只用that。 d）先行詞為序數(shù)詞、數(shù)詞、形容詞最高級(jí)時(shí)，只用that。. e）先行詞既有人，又有物時(shí)。例如： All that is needed is a supply of oil. 所需的只是供油問(wèn)題。 Finally, the thief handed everything that he had stolen to the police. 那賊最終把偷的全部東西交給了警察。19. 狀語(yǔ)從句 19.1 地點(diǎn)狀語(yǔ)從句地點(diǎn)狀語(yǔ)從句通常由where, wherever 引導(dǎo)。例如：Where I live there are plenty of tre

38、es. 我住的地方樹(shù)很多。Wherever I am I will be thinking of you. 不管我在哪里我都會(huì)想到你。 19.2 方式狀語(yǔ)從句 方式狀語(yǔ)從句通常由as, （just） asso, as if, as though引導(dǎo)。1）as, （just） asso引導(dǎo)的方式狀語(yǔ)從句通常位于主句后，但在（just） asso結(jié)構(gòu)中位于句首，這時(shí)as從句帶有比喻的含義，意思是"正如"，"就像"，多用于正式文體。例如： Always do to the others as you would be done by. 你希望人家怎樣待你，你就

39、要怎樣待人。As water is to fish, so air is to man. 我們離不開(kāi)空氣，猶如魚(yú)兒離不開(kāi)水。Just as we sweep our rooms, so we should sweep backward ideas from our minds. 正如打掃房屋一樣，我們也要掃除我們頭腦中落后的東西。2）as if, as though 兩者的意義和用法相同，引出的狀語(yǔ)從句謂語(yǔ)多用虛擬語(yǔ)氣，表示與事實(shí)相反，有時(shí)也用陳述語(yǔ)氣，表示所說(shuō)情況是事實(shí)或?qū)崿F(xiàn)的可能性較大。漢譯常作"仿佛似的"，"好像似的"。例如： They compl

40、etely ignore these facts as if （as though） they never existed. 他們完全忽略了這些事實(shí)，就仿佛它不存在似的。（與事實(shí)相反，謂語(yǔ)用虛擬語(yǔ)氣。）He looks as if （as though） he had been hit by lighting. 他那樣子就像被雷擊了似的。（與事實(shí)相反，謂語(yǔ)用虛擬語(yǔ)氣。） It looks as if the weather may pick up very soon. 看來(lái)天氣很快就會(huì)好起來(lái)。（實(shí)現(xiàn)的可能性較大，謂語(yǔ)用陳述語(yǔ)氣。） 說(shuō)明：as if / as though也可以引導(dǎo)一個(gè)分詞短語(yǔ)

41、、不定式短語(yǔ)或無(wú)動(dòng)詞短語(yǔ)。例如： He stared at me as if seeing me for first time. 他目不轉(zhuǎn)睛地看著我，就像第一次看見(jiàn)我似的。He cleared his throat as if to say something. 他清了清嗓子，像要說(shuō)什么似的。The waves dashed on the rocks as if in anger. 波濤沖擊著巖石，好像很憤怒。19.3 原因狀語(yǔ)從句 比較because, since, as和for： 1）because語(yǔ)勢(shì)最強(qiáng)，用來(lái)說(shuō)明人所不知的原因，回答why提出的問(wèn)題。當(dāng)原因是顯而易見(jiàn)的或已為人們所知，就

42、用as或 since。例如： I didn't go, because I was afraid. 我不去是因?yàn)槲遗隆?Since /As the weather is so bad, we have to delay our journey. 天氣那么糟，旅行推遲了。2）由because引導(dǎo)的從句如果放在句末，且前面有逗號(hào)，則可以用for來(lái)代替。但如果不是說(shuō)明直接原因，而是多種情況加以推斷，就只能用for。例如： He is absent today, because / for he is ill. 他今天缺席，因?yàn)樗×恕?He must be ill, for he is ab

43、sent today. 他一定病了，所以今天缺席。19.4 目的狀語(yǔ)從句 表示目的狀語(yǔ)的從句可以由that, so that, in order that, lest, for fear that, in case等詞引導(dǎo)。例如： You must speak louder so that /in order that you can be heard by all. 你必須大點(diǎn)聲，別人就能聽(tīng)見(jiàn)了。 He wrote the name down for fear that（lest） he should forget it. 他寫(xiě)下了這個(gè)名字以免以后忘記。 Better take more c

44、lothes in case the weather is cold. 最好多穿點(diǎn)衣服，以防天發(fā)冷。 19.5 結(jié)果狀語(yǔ)從句 結(jié)果狀語(yǔ)從句常由sothat 或 suchthat引導(dǎo)。sothat與suchthat之間可以轉(zhuǎn)換。例如： The boy is so young that he can't go to school. 這男孩年齡太小，不能上學(xué)。 He is such a young boy that he can't go to school 19.6 條件狀語(yǔ)從句 連接詞主要有 if, unless, as/so long as, on condition

45、 that 等。if 引導(dǎo)的條件句有真實(shí)條件句和非真實(shí)條件句兩種。非真實(shí)條件句已在虛擬語(yǔ)氣中闡述。 unless = if not. 例如： Let's go out for a walk unless you are too tired. 如果不太累，我們?nèi)ド⑸⒉健?If you are not too tied, let's go out for a walk.典型例題You will be late _ you leave immediately. A. unless B. until C. ifD. or 答案A。句意：除非你立即走，否則你就回遲到的。可轉(zhuǎn)化為 If y

46、ou dong leave immediately, you will be late。B、D句意不對(duì)，or表轉(zhuǎn)折，句子如為 You leave immediately or you will be late. 19.7 讓步狀語(yǔ)從句 1）though, although引導(dǎo)的讓步狀語(yǔ)從句，后面的從句不能有but，但是 though 和yet可連用。例如：Although it's raining, they are still working in the field.雖然在下雨，但他們?nèi)栽诘乩锔苫睢?He is very old, but he still works very h

47、ard. 雖然他很老了，但仍然努力地工作。Though the sore be healed, yet a scar may remain. 傷口雖愈合，但傷疤留下了。（諺語(yǔ)）2） as, though 引導(dǎo)的讓步從句必須表語(yǔ)或狀語(yǔ)提前（形容詞、副詞、分詞、實(shí)義動(dòng)詞提前）。例如：Child as /though he was, he knew what was the right thing to do.雖然是個(gè)小孩，該做什么不做什么，他全知道。3） ever if, even though即使。例如： We'll make a trip even though the weather

48、 is bad. 即使天氣不好，我們也要去遠(yuǎn)足。4） whetheror不管都。例如： Whether you believe it or not, it is true. 信不信由你，這確實(shí)是真的。5）"no matter +疑問(wèn)詞" 或"疑問(wèn)詞+后綴ever" 。例如： No matter what happened, he would not mind. =Whatever happened, he would not mind. 不管發(fā)生什么，他不在意。替換：no matter what = whatever no matter who = wh

49、oever no matter when = whenever no matter where = wherever no matter which = whichever no matter how = however 注意：no matter 不能引導(dǎo)主語(yǔ)從句和賓語(yǔ)從句。 （錯(cuò)）No matter what you say is of no use now. （對(duì)）Whatever you say is of no use now. 你現(xiàn)在說(shuō)什么也沒(méi)用了。（Whatever you say是主語(yǔ)從句）（錯(cuò)）Prisoners have to eat no matter what they&

50、#39;re given, （對(duì)）Prisoners have to eat whatever they're given.囚犯?jìng)冎荒芙o什么吃什么。 19.8 比較while, when, as 1）as, when 引導(dǎo)短暫性動(dòng)作的動(dòng)詞。例如： Just as / Just when / When I stopped my car, a man came up to me. 我一剎車(chē)，有一個(gè)人向我走來(lái)。2）當(dāng)從句的動(dòng)作發(fā)生于主句動(dòng)作之前，只能用when 引導(dǎo)這個(gè)從句，不可用as 或 while。例如： When you have finished your work, you may

51、 have a rest. 趕完活后，你可以休息一下。3）從句表示"隨時(shí)間推移"連詞能用as，不用when 或while。例如： As the day went on, the weather got worse.日子一天天過(guò)去，天氣越變?cè)綁摹?9.9 比較until和till 此兩個(gè)連詞意義相同。肯定形式表示的意思是"做某事直至某時(shí)"，動(dòng)詞必須是延續(xù)性的。否定形式表達(dá)的意思是"直至某時(shí)才做某事"。動(dòng)詞為延續(xù)性或非延續(xù)性都可以。正確使用這兩個(gè)連詞的關(guān)鍵之一就在于判斷句中的動(dòng)詞該用肯定式還是否定式?？隙ň洌篒 slept until m

52、idnight. 我一直睡到半夜時(shí)醒了。 Wait till I call you. 等著我叫你。（在肯定句中可用before代替。例如 Let's get in the wheat before the sun sets.） 否定句：She didn't arrive until 6 o'clock. 她直到6點(diǎn)才到。 Don't get off the bus until it has stopped. 公共汽車(chē)停穩(wěn)后再下車(chē)。I didn't manage to do it until you had explained how. 直到你教我后，我才

53、會(huì)做。 區(qū)別：1）until可用于句首，而till通常不用于句首。例如： Until you told me, I had heard nothing of what happened. 直到你告訴我以前，出了什么事我一點(diǎn)也不知道。 2）until when 疑問(wèn)句中，until要放在句首。例如： -Until when are you staying?你呆到什么時(shí)候？- Until next Monday.呆到下周一。注意：否定句可用另外兩種句式表示。1）Not until在句首，主句用倒裝。例如： Not until the early years of the 19th century

54、did man know what heat is. 直到19 世紀(jì)初，人類(lèi)才知道熱為何物。 Not until I began to work did I realize how much time I had wasted. 直到工作，才認(rèn)識(shí)到我已蹉跎了幾多歲月。2）It is not until that 。例如： It was not until I began to work that I realized how much time I had wasted.19.10 表示"一就"的結(jié)構(gòu) hardly/scarcelywhen/before, no soone

55、rthan和as soon as都可以表示"一就"的意思。例如： I had hardly / scarcely got home when it began to rain. 剛回家，就下起雨來(lái)了。 I had no sooner got home than it began to rain. As soon as I got home, it began to rain. 注意：如果hardly, scarcely 或no sooner置于句首，句子必須用倒裝結(jié)構(gòu)。例如： Hardly / Scarcely had I got home when it began to rain. No sooner had I got home than it began to rain. 20. 連詞 連詞不能獨(dú)立擔(dān)任句子成分而只