英语语法从句讲解.doc

1、1从 句 从句按其在主句中的句法功能可分为三类:即名词性从句、形容词性从句(即定语从句) 和副词性从句(即状语从句)。引导从句的词称作关联句.一、名词性从句引导这些名词性从句的关联词包括:从属连词 that, if, whether;连接代词who,whoever,whom,whomever,which,whichever,what,whatever,whose;连接副词 where, when, why, how。其中, 从属连词只起连接作用, 在从句中不充当任何句法成分,而连接代词和连接副词既起连接作用, 在从句中又充当一定的成分.That Owen should have married

2、 his cousin is not at all surprising.The fact is that he didnt go to the dinner party.I dont know if he will attend the meeting.Have you heard the news that Mary is going to marry Tom?你听说玛丽要和汤姆结婚的消息了吗?(that 引导同位语从句)提示21. 在含有主语从句的复合句中, 为保持句子平衡 , 常用 it 作形式主语,而将真正的主语从句置于句末.Its well-known that water is

3、indispensable to life.(形式主语)2. 为保持句子平衡, that 引导的宾语从句也常用 it 代替, 而将真正的宾语从句置于主句句末。这常常出现在主句有形容词或分词作宾语补足语的情况下。He made it quite clear that he preferred to live here.3. 从属连词 whether 和 if 都作“是否”解, 但 if 不可引导主语从句和表语从句。whether 可与 or(not)连用, 而 if 不可以。I dont know whether (if) she is at home.Whether she comes or

4、not makes no difference.4. that 和 what 引导名词性从句的区别 : that 在从句中不充当成分, 而what 在从句中充当一定的成分 , 如主语、表语、宾语等。that 可省略, what 则不可省。He always means what he says.She suggested (that) he do it at once.5. 同位语从句大多由从属连词 that 引导, 常跟在下列名词后面, 如fact, idea, opinion, news, hope, belief 等, that 不可省。同位语从句一般用来解释说明这些名词的具体含义和内容

5、。We are familiar with the idea that all matter consists of atoms.3The news that we are invited to the conference is very encouraging.二、定语从句引导定语从句的关联词包括:(1)关系代词:that, which, whose, who, whom, as;(2)关系副词:when, where, why。关系代词和关系副词在定语从句中都充当一定的句法成分,关系代词在句中充当动词的宾语时, 一般可省去。关系代词的选用比较复杂, 它受下列条件的制约:(1)先行词是指人

6、还是指物;(2)关系代词在从句中的句法功能;(3)定语从句是限定性的还是非限定性的。关系代词的选用情况见下表 : 先行词在从句中的句法功能 用于限定性或非限定性定语从句 只用于限定性定语从句指人或指物 指人 指物主语 who which that宾语 whom which that定语 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(礼貌)。4The watch whic

7、h (that) was lost has been found.Here is the meterial which (that) you need.Youre the only one whose advice he might listen to.关系副词的选用相对来说较简单。如先行词为表示时间的名词, 如time, day 等, 则用 when; 如先行词为表示地点的名词, 如 place, house, area 等,则用 where; 如先行词为 reason, 则用 why。Ill never forget the mountain village where (in which

8、) I spent my childhood.I dont know the reason why (for which) he did that.提示1. 当先行词是 all, something, nothing 等不定代词时; 或先行词前有first,last, only, few, much, some, any, no 等修饰时;或先行词前有形容词最高级修时, 一般只用 that 而不用 which 来引导定语从句。Ive explained everything (that) I can to you.This is the most beautiful compus (that)

9、 Ive ever been to.2. 定语从句分为限定性定语从句和非限定性定语从句, 限定性定语从句与主句关系紧密, 为句中不可缺少的部分, 如去掉, 主句意思不完整。非限定性定语从句与主句关系松散, 如去掉, 主句内容仍完整。在书面语中, 非限定性定语从句一般被逗句隔开。非限定性定语从句一般不用 that 引导。引导非限定性定语从句的关系词不可省略。His speech, which bored everyone, went on and on.5The generals daughter, whose name is Ann, gave me a sweet smile.3. 先行词也

10、可以是整个句子。这时, 一般用 which 或 as 来引导定语从句。 which 在从句中可充当主语、宾语等, as 在从句中一般只充当主语。which 与 as 引导此类定语从句的区别在于 : which 只能置于句中或句末, 而 as 的位置比较灵活, 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 had be

11、en expected, he finished first in decathlon(十项全能) at that Olympic Games.4. 关系代词在定语从句中有时也做介词的宾语。如果介词被置于关系代词前, 一般只用介词+which 或介词+whom, 而不用介词+that来此导定语从句。如果介词被置于从句句末, 则可用 that 代替which 或 whom,且 that 这时可省去。This is the ring on which she spent 1,000 dollars.One of my colleagues whom (that) you are familiar

12、with will come today.三、状语从句在复合句中, 起状语作用的从句称作状语从句。根据语义, 状语从句分为:6时间状语从句、地点状语从句、条件状误从句、原因状语从句、让步状语从句、比较状语从句、目的状语从句、结果状语从句、方式状语从句。状语从句可放在句首或句末。如状语从句位于主语前,一般用逗号将其与主句隔开。(一) 时间状语从句When you cross a main road, you must be very careful.Until we learn the facts, we cant do anything about it.提示1. when, as, whil

13、e 引导时间状语从句时都可以表示主句的动作与从句的动作同时发生, 即同时性。它们的区别在于:when 和 as 引导的状语从句中的动作既可以是延续性的, 也可以是非延续性的, 即瞬时性的;while 引导的状语从句中的动作只能是延续的动作或状态。当主句和从句中的动作均为延续动作时, 一般用 while, 而不用when 或 as。当表示两个同时发展、变化的情况时, 一般用 as, 作“随着” 解。When she comes, I shall tell her to wait for you.As she got older, she got wiser.While Peter was rea

14、ding, his wife was cooking.72. 有些副词和一些表示时间的名词词组也可用作从属连词,引导时间状语从句。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) 条件状语从句引导条件状语从句的从

15、属连词有:if, unless, as (so) long as, only if(只要)。If you dont come on time, well start out without you.As (so) long as you keep on trying, youll certainly succeed.提示除了以上提到的从属连词外, 还有其它的一些词或词组也可引导条件状语从句。如: providing that, provided, supposing that, suppose that, on condition that, in case 等。Provided (that)

16、 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.要是我的费用有人代付我就去Supposing he is not at home, what then?假如他不在家 ,那怎么办?8You can use the bicycle on condition that you return it tomorrow.只要你明天归还,自行车你可以拿去用。In case she comes back,

17、let me know immediately.假使她回来了,立刻告诉我Take the raincoat in case it rains.带着雨衣,以防下雨。(三) 原因状语从句引导原因状语从句从句的从属连词有: becasue, since, as, now(that), in that, considering that 等。Since the speaker cant come, well have to cancel the meeting.Considering hes only been learning English a year he speaks it very wel

18、l.考虑到他只学了一年英语,他讲得算是很流利了。We didnt know what to do as we were just visiting there.我们不知道该怎么办,因为当时我们仅仅在那里作访问。Since it is so hot, lets go swimming.既然天气这么热, 我们去游泳吧。提示in that 和 now(that)的用法: in that 引导的从句对主句进行解释和说明,意思是: 在方面, 在于; 因为。now(that)表示既然。Theory is valuable in that it can provide a direction for pra

19、ctice.理论所以有价值,就在于它能给实践指出方向。Now (that) the weather has improved, lets go out for a picnic.既然天气已转好, 我们就出去野餐吧。9(四) 让步状语从句引导让步状语从句的从属连词有: though, although, even if (even though), as, no matterdespite the fact that, in spite of the fact that, while。Tom always enjoys swimming, even though the weather is r

20、ough.Despite the fact that there exists national differences,certain funny situations have a universal appeal.Tired as he was, he sat up late.他虽然疲倦, 可仍然很晚才睡。No matter how they slander us, we will never give in.不管他们怎样诽谤我们,我们决不让步。While I like the color of the hat, I do not like its shape.虽然我喜欢这顶帽子的颜色,

21、但我不喜欢它的形状。提示一些疑问词在词尾加上 ever 后, 也可引导让步状语从句,相当于 no matter+疑问词。这些词包括: whatever, wherever, whenever, whoever, however。Whatever he says, dont beleve him.Whoever you are, you must obey the traffic regulations.(五 )目的状语从句引导目的状语从句的从属连词有: so that, in order that, lest, in case, for fear that。10They climbed to

22、the top of the building in order that they could get a birds-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.我们不敢开他玩笑生怕他动气。提示so that 和 in order that 的区别: so that 更常用, in or

23、der that 更正式。so that 引导的从句一般置于句末,而 in order that 引导的从句既可置于句首, 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) 结果状语从句结果状语从句一般由下列连词引导: so that, sothat, suchthat。He overslept, (so) that he was late for work.They got such a fright that they dropped the bag and ran away.提示1. sothat 和 suchthat 的区别。so 后接形容词或副词, such 后接名词。It was so cold that we had to cancel the game.Its such a good chance that we mustnt miss it.