英語語法從句講解

1、從 句 從句按其在主句中的句法功能可分為三類: 即名詞性從句、形容詞性從句(即定語從句)和副詞性從句(即狀語從句)。 引導(dǎo)從句的詞稱作關(guān)聯(lián)句.一、名詞性從句引導(dǎo)這些名詞性從句的關(guān)聯(lián)詞包括: 從屬連詞that, if, whether;連接代詞who,whoever,whom,whomever,which,whichever,what,whatever,whose; 連接副詞where, when, why, how。其中, 從屬連詞只起連接作用, 在從句中不充當任何句法成分,而連接代詞和連接副詞既起連接作用, 在從句中又充當一定的成分.That Owen should have married

2、 his cousin is not at all surprising.The fact is that he didn't go to the dinner party.I don't know if he will attend the meeting.Have you heard the news that Mary is going to marry Tom?你聽說瑪麗要和湯姆結(jié)婚的消息了嗎?(that引導(dǎo)同位語從句)提示1. 在含有主語從句的復(fù)合句中, 為保持句子平衡, 常用it作形式主語,而將真正的主語從句置于句末.It's well-known that

3、 water is indispensable to life.(形式主語)2. 為保持句子平衡, that引導(dǎo)的賓語從句也常用it代替, 而將真正的賓語從句置于主句句末。這常常出現(xiàn)在主句有形容詞或分詞作賓語補足語的情況下。He made it quite clear that he preferred to live here.3. 從屬連詞whether和if都作“是否”解, 但if不可引導(dǎo)主語從句和表語從句。whether可與or(not)連用, 而if不可以。I don't know whether (if) she is at home.Whether she comes o

4、r not makes no difference.4. that和what引導(dǎo)名詞性從句的區(qū)別: that在從句中不充當成分,而what在從句中充當一定的成分, 如主語、表語、賓語等。that可省略, what則不可省。He always means what he says.She suggested (that) he do it at once.5. 同位語從句大多由從屬連詞that引導(dǎo), 常跟在下列名詞后面, 如fact, idea, opinion, news, hope, belief等, that不可省。同位語從句一般用來解釋說明這些名詞的具體含義和內(nèi)容。We are fami

5、liar with the idea that all matter consists of atoms.The news that we are invited to the conference is very encouraging.二、定語從句引導(dǎo)定語從句的關(guān)聯(lián)詞包括:(1)關(guān)系代詞:that, which, whose, who, whom, as;(2)關(guān)系副詞:when, where, why。關(guān)系代詞和關(guān)系副詞在定語從句中都充當一定的句法成分,關(guān)系代詞在句中充當動詞的賓語時, 一般可省去。關(guān)系代詞的選用比較復(fù)雜, 它受下列條件的制約:(1)先行詞是指人還是指物;(2)關(guān)系代詞在

6、從句中的句法功能;(3)定語從句是限定性的還是非限定性的。關(guān)系代詞的選用情況見下表: 先行詞在從句中的句法功能 用于限定性或非限定性定語從句 只用于限定性定語從句指人或指物 指人  指物主語 who which that賓語 whom which that定語 whose  whose(of which)I know that he is a man who (that) means what be says.The gentleman whom (that) she met addressed her with courtesy(禮貌)。The wat

7、ch which (that) was lost has been found.Here is the meterial which (that) you need.You're the only one whose advice he might listen to.關(guān)系副詞的選用相對來說較簡單。如先行詞為表示時間的名詞, 如time, day等, 則用when; 如先行詞為表示地點的名詞, 如place, house, area等,則用where; 如先行詞為reason, 則用why。I'll never forget the mountain village where

8、 (in which) I spent my childhood.I don't know the reason why (for which) he did that.提示1. 當先行詞是all, something, nothing等不定代詞時;或先行詞前有first,last, only, few, much, some, any, no等修飾時;或先行詞前有形容詞最高級修時, 一般只用that而不用which來引導(dǎo)定語從句。I've explained everything (that) I can to you.This is the most beautiful c

9、ompus (that) I've ever been to.2. 定語從句分為限定性定語從句和非限定性定語從句, 限定性定語從句與主句關(guān)系緊密, 為句中不可缺少的部分, 如去掉, 主句意思不完整。非限定性定語從句與主句關(guān)系松散, 如去掉, 主句內(nèi)容仍完整。在書面語中, 非限定性定語從句一般被逗句隔開。非限定性定語從句一般不用that引導(dǎo)。引導(dǎo)非限定性定語從句的關(guān)系詞不可省略。His speech, which bored everyone, went on and on.The general's daughter, whose name is Ann, gave me a

10、sweet smile.3. 先行詞也可以是整個句子。這時, 一般用which或as來引導(dǎo)定語從句。 which在從句中可充當主語、賓語等, as在從句中一般只充當主語。which與as引導(dǎo)此類定語從句的區(qū)別在于: which只能置于句中或句末, 而as的位置比較靈活, 可置于句中、句末, 又可置于句首。Water consists of hydrogen and oxygen, which (as) is known to all.He was awarded a gold medal, which the whole family considered a great honor.As h

11、ad been expected, he finished first in decathlon(十項全能) at that Olympic Games.4. 關(guān)系代詞在定語從句中有時也做介詞的賓語。如果介詞被置于關(guān)系代詞前, 一般只用介詞+which或介詞+whom, 而不用介詞+that來此導(dǎo)定語從句。如果介詞被置于從句句末, 則可用that代替which或whom,且that這時可省去。This is the ring on which she spent 1,000 dollars.One of my colleagues whom (that) you are familiar wi

12、th will come today.三、狀語從句在復(fù)合句中, 起狀語作用的從句稱作狀語從句。 根據(jù)語義, 狀語從句分為: 時間狀語從句、地點狀語從句、條件狀誤從句、原因狀語從句、 讓步狀語從句、比較狀語從句、目的狀語從句、結(jié)果狀語從句、 方式狀語從句。狀語從句可放在句首或句末。如狀語從句位于主語前,一般用逗號將其與主句隔開。(一)時間狀語從句When you cross a main road, you must be very careful.Until we learn the facts, we can't do anything about it.提示1. when, as,

13、 while引導(dǎo)時間狀語從句時都可以表示主句的動作與從句的動作同時發(fā)生, 即同時性。它們的區(qū)別在于: when和as引導(dǎo)的狀語從句中的動作既可以是延續(xù)性的, 也可以是非延續(xù)性的, 即瞬時性的;while引導(dǎo)的狀語從句中的動作只能是延續(xù)的動作或狀態(tài)。當主句和從句中的動作均為延續(xù)動作時, 一般用while, 而不用when或as。當表示兩個同時發(fā)展、變化的情況時, 一般用as, 作“隨著”解。When she comes, I shall tell her to wait for you.As she got older, she got wiser.While Peter was reading

14、, his wife was cooking.2. 有些副詞和一些表示時間的名詞詞組也可用作從屬連詞,引導(dǎo)時間狀語從句。如instantly, immediately, directly, the day, every time, the minute, the second, the moment等。Immediately he arrived, he started describing us what had happened.The day he returned home, his grandpa was alrady dead.(二)條件狀語從句引導(dǎo)條件狀語從句的從屬連詞有: if

15、, unless, as (so) long as, only if(只要)。If you don't come on time, we'll start out without you.As (so) long as you keep on trying, you'll certainly succeed.提示除了以上提到的從屬連詞外, 還有其它的一些詞或詞組也可引導(dǎo)條件狀語從句。如: providing that, provided, supposing that, suppose that, on condition that, in case等。Provided

16、 (that) he wins the support of the minority groups,he will be able to win the electrion.I will go providing that my expenses are paid.要是我的費用有人代付我就去Supposing he is not at home, what then?假如他不在家,那怎么辦?You can use the bicycle on condition that you return it tomorrow.只要你明天歸還,自行車你可以拿去用。In case she comes b

17、ack, let me know immediately.假使她回來了,立刻告訴我Take the raincoat in case it rains.帶著雨衣,以防下雨。(三)原因狀語從句引導(dǎo)原因狀語從句從句的從屬連詞有: becasue, since, as, now(that), in that, considering that等。Since the speaker can't come, we'll have to cancel the meeting.Considering he's only been learning English a year he

18、speaks it very well.考慮到他只學(xué)了一年英語,他講得算是很流利了。We didn't know what to do as we were just visiting there.我們不知道該怎么辦,因為當時我們僅僅在那里作訪問。Since it is so hot, let's go swimming.既然天氣這么熱,我們?nèi)ビ斡景?。提示in that和now(that)的用法: in that引導(dǎo)的從句對主句進行解釋和說明,意思是: 在方面, 在于; 因為。now(that)表示既然。Theory is valuable in that it can pro

19、vide a direction for practice.理論所以有價值,就在于它能給實踐指出方向。Now (that) the weather has improved, let's go out for a picnic.既然天氣已轉(zhuǎn)好, 我們就出去野餐吧。(四)讓步狀語從句引導(dǎo)讓步狀語從句的從屬連詞有: though, although, even if (even though), as, no matterdespite the fact that, in spite of the fact that, while。Tom always enjoys swimming, e

20、ven though the weather is rough.Despite the fact that there exists national differences,certain funny situations have a universal appeal.Tired as he was, he sat up late.他雖然疲倦,可仍然很晚才睡。No matter how they slander us, we will never give in.不管他們怎樣誹謗我們,我們決不讓步。While I like the color of the hat, I do not li

21、ke its shape.雖然我喜歡這頂帽子的顏色,但我不喜歡它的形狀。提示一些疑問詞在詞尾加上ever后, 也可引導(dǎo)讓步狀語從句,相當于no matter+疑問詞。這些詞包括: whatever, wherever, whenever, whoever, however。Whatever he says, don't beleve him.Whoever you are, you must obey the traffic regulations. (五)目的狀語從句引導(dǎo)目的狀語從句的從屬連詞有: so that, in order that, lest, in case, for

22、fear that。They climbed to the top of the building in order that they could get a bird's-eye view of the city.Ask her to hurry up with these letters so that I can sign them.Take an umbrella in case it rains.We dare not play jokes on him lest he should become angry.我們不敢開他玩笑生怕他動氣。提示so that和in order that的區(qū)別: so that更常用, in order that更正式。so that引導(dǎo)的從句一般置于句末,而in order that引導(dǎo)的從句既可置于句首, 又可置于句末。In order that the grass and flowers could bloom again,it was necessary that the rocks should be removed.She got up early so that she could catch the first bus.(六)結(jié)果狀語從句結(jié)果狀語從句一般由下列連詞引導(dǎo):