高中英语所有从句大全

1、精选优质文档-倾情为你奉上高中英语从句大全1）表语从句1.定义：用作表语的从句叫做表语从句。2.构成：关联词+简单句3.引导表语从句的关联词的种类：（1）从属连词that.如：The trouble is that I have lost his address.麻烦是我把他的地址丢了。（2）从属连词whether，as，as if.如：He looked just as he had looked ten years before.他看起来还与十年前一样。The question is whether they will be able to help us.问题是他们是否能帮我们。注：从属

2、连词if一般不用来引导表语从句，但as if却可引导表语从句，如：All this was over twenty years ago，but its as if it was only yesterday.这都是20多年前的事了，但宛如昨天一样。能跟表语从句的谓语动词一般为系动词be，seem，look等。如：It looked as if it was going to rain.看起来天要下雨了。（3）连接代词who，whom，whose，what，which，whoever，whatever，whichever连接副词 where，when，how，why.如：The problem

3、is who we can get to replace her.问题是我们能找到谁去替换她呢。The question is how he did it.问题是他是如何做此事的。That was what she did this morning on reaching the attic.那就是她今晨上了阁楼干的。解释：1.连词because可引导表语从句。如：I think it is because you are doing too much.我想这是因为你做得太多。2.在一些表示“建议、劝说、命令”的名词后面的表语从句中，谓语动词用虚拟语气。should+动词原形表示，should

4、可省略。如：My suggestion is that we （should）start early tomorrow.我的建议是我们明天一早就出发。2）主语从句1.定义：用作主语的从句叫做主语从句。2.构成：关联词+简单句3.引导主语从句的关联词有三类：（1）从属连词that.如：That they were in truth sisters was clear from the facial resemblance between them.很明显，她们确是亲姐妹，她们的脸型很相似。（2）从属连词whether.如：Whether hell come here isnt clear.他是否

5、会来这里还不清楚。（3）连接代词who，whom，whose，what，which，whoever，whatever，whichever连接副词 where，when，how，why.如：What she did is not yet known.她干了什么尚不清楚。How this happened is not clear to anyone.这事怎样发生的，谁也不清楚。Whoever comes is welcome.不论谁来都欢迎。Wherever you are is my home my only home.你所在的任何地方就是我的家我唯一的家。解释：1.主语从句能用it作形式上的

6、主语。常以it作形式主语的句型有：A.It+be+形容词（obvious，true，natural，surprising，good，wonderful，funny，possible，likely，certain，probable，etc.）+that从句。如：It is certain that she will do well in her exam.毫无疑问她考试成绩会很好。It is probable that he told her everything.很可能他把一切都告诉她了。B.It+be+名词词组（no wonder，an honor，a good thing，a pity，n

7、o surprise，etc.）+that从句。如：Its a pity that we cant go.很遗憾我们不能去。Its no surprise that our team should have won the game.我们没赢这场比赛真意外。C.It+be+过去分词（said，reported，thought，expected，decided，announced，arranged，etc.）+that从句。如：It is said that Mr.Green has arrived in Beijing.据说格林先生已经到了北京。It is reported that Chin

8、a has sent another man-made earth satellite into orbit.据报道中国又成功地发射了一颗人造地球卫星。D.It+seem，happen等不及物动词及短语+that从句。如：It seems that Alice is not coming to the party at all.Alice似乎不来参加晚会。It happened that I was out that day.碰巧我那天外出了。E.It+doesnt matter（makes no difference，etc.）+连接代词或连接副词引起的主语从句。如：It doesnt ma

9、tter whether she will come or not.她是否来这无关紧要。It makes no difference where we shall have the meeting.我们在哪里开会毫无区别。F.当that引导的主语从句出现在疑问句中时，要以it作形式主语，而把主语从句后置。如：Is it true that the scientist will give us a lecture next week？ 下周那位科学家将给我们作报告是真的吗？Does it matter much that they will not come tomorrow？ 他们明天不来很要

10、紧吗？G.当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置。如：How strange it is that the children are so quiet！ 孩子们这么安静真奇怪！2.注意连接代词whoever，whatever，whichever等引导主语从句的含义。Whoever comes will be welcome.（whoever=the person who）来的人将受到欢迎。Whatever he did was right.（whatever=the thing that）他所做的事情是正确的。Whichever of you comes in wil

11、l receive a prize.（whichever=anyone of you who）你们当中不论哪个进来将会得到奖3）宾语从句1.定义：用作宾语的从句叫宾语从句。2.构成：关联词+简单句。3.引导宾语从句的关联词有三类：（1）从属连词that.如：He told us that he felt ill.他对我们说他感到不舒服。I know he has returned.我知道他已经回来了。注： that在引导宾语从句时也并不是任何情况下都可以省略。在以下情况下，that不能省略。1.Everybody could see what happened and that Tom was

12、 frightened.（and连接两个宾语从句，that宾语从句放在and的后面时，that不能省略。）大家都会看出所发生的事情并知道Tom非常害怕。2.I know nothing about him except that he is from the south.（that引导的宾语从句作介词宾语时，that不能省略。）对他我一无所知，只知道他是南方人。3.That he ever said such a thing I simply dont believe.（that从句位于句首时，that不可省略。）我简直不相信他曾说过这样的话。4.We decided，in view of h

13、is special circumstances，that we would admit him for a probationary period.（主句谓语动词与that从句之间有插入语，that不可省略。）鉴于他的特殊情况，我们决定应允他一段试用期。（2）从属连词if/whether.如：I doubt whether he will succeed.我怀疑他是否会成功。I dont know if you can help me.我不知道你能否帮助我。（3）连接代词who，whom，whose，what，which，whoever，whatever，whichever连接副词 wher

14、e，when，how，why.如：Who or what he was，Martin never learned.他是什么人？他是干什么的？马丁根本不知道。I wonder what hes writing to me about.我不知道他要给我写信说什么事。Ill tell you why I asked you to come.我会告诉你我为什么要你来。You may do what you will.你可做任何你想做的事。（1）介词宾语从句宾语从句也可用作介词的宾语。如：He was deeply displeased by what had occurred that day.他对那

15、天发生的事感到很不快。I walked over to where she sat.我走向她坐的地方。I am curious as to what he will say.我很想知道他要说什么。Your success will largely depend upon what you do and how you do it.你是否成功将主要取决于你做什么和怎样做。有时介词可以省略。如：I dont care （for）who marries him.我不管谁跟他结婚。Be careful （as to）how you do that.你要注意做这件事的方式。解释：1.如果宾语从句后还有宾

16、语补足语，则用it作形式宾语，而将宾语从句后置。如：We thought it strange that Xiao Wang did not come yesterday.我们认为小王昨天没来是奇怪的。He has made it clear that he will not give in.他已表明他不会屈服。2.作介词的宾语：连词that引导的名词性从句很少作介词的宾语，只用在except，but，in后。其他一些介词的宾语从句如果由连词that引导，则需用it先行一步，作形式宾语。如：He is a good student except that he is careless.他是一个

17、好学生，只是有点粗心。You may rely on it that I shall help you.你可以指望我会帮助你的。介词宾语不可以用which来引导，而要用what来引导。如：Are you sorry for what youve done？你为你所做的一切感到内疚吗？3.某些形容词或过去分词后常接宾语从句，这类形容词或过去分词有sure，glad，certain，pleased，happy，afraid，surprised，satisfied等，连词that可省略。如：I am not sure what I ought to do.我不能确定我该做什么。Im afraid y

18、ou dont understand what I said.恐怕你没领会我说的意思。Im surprised that I didnt see all that before.我好奇怪，我以前没看到过。Mother was very pleased her daughter had passed the exams.妈妈为她的女儿通过了考试而感到高兴。4.连词whether （or not）或if引导的宾语从句if和whether引导的宾语从句可以互换使用，但whether常和or not连用，if一般不与or not连用。如：I wonder whether it is true or n

19、ot.我不知它是真是假。用if引导宾语从句如果会引起歧义，应避免使用if而用wheter.试比较：Please let me know if you want to go.Please let me know whether you want to go.if从句可理解为宾语从句，意为“请告诉我你是否想去”；此句又可理解为条件状语从句意为“如果你想去的话，请告诉我一声”。5.宾语从句的否定转移。在think，believe，suppose，expect等动词后的宾语从句，有时谓语尽管是否定意思，却不用否定形式，而将think等动词变为否定形式。如：I dont think you are ri

20、ght.我认为你错了。I dont believe they have finished their work yet.我相信他们还未完成他们的工作。I dont suppose he cares，does he？ 我想他不在意，是吗？6.宾语从句的时态变化规律：（1）当主句是一般现在时态时，从句可根据需要用任何时态。（2）当主句是一般过去时态时，从句只能使用过去范围内的任何时态。但客观真理除外。如：The teacher said that the earth goes round the sun.说地球绕着太阳运行。4）同位语从句1.定义：用作同位语的从句叫做同位语从句。2.用法：同位语从

21、句的先行词多为fact，news，idea，thought，question，reply，report，remark等，关联词多用从属连词that.如：They were all very much worried over the fact that you were sick.对你生病这件事，他们都很焦虑。Where did you get the idea that I could not come？你在哪儿听说我不能来？Early in the day came the news that Germany had declared war on Russia.德国已对俄国宣战的消息一大

22、早就传来了。注：同位语从句偶尔由从属连词whether引导。如：I have no idea whether hell come or not.我不知道他是否来。连接代词who，which，what和连接副词where，when，why，how亦可引导同位语从句。The question who should do the work requires consideration.谁该干这项工作，这个问题需要考虑。We havent yet settled the question where we are going to spend our summer vacation.到哪儿去度暑假，这

23、个问题我们还没有决定。It is a question how he did it.那是一个他如何做了此事的问题。解释：1.that引导的同位语从句与定语从句之区别that引导的同位语从句that引导的定语从句句法功能上that只起连接从句的作用，无意义。在从句中不充当句子成分。不可省。that替代先行词在从句中不仅起连接作用，还充当一个句子成分。如在从句中作动词的宾语时可省略。意义上从句是被修饰名词的内容。从句起限定作用，是定语如：The news that Mr.Li will be our new English teacher is true.（同位语从句，that不可省。）李先生将是

24、我们的新英语老师这个消息是真的。The news （that）he told me yesterday is true.（定语从句，that在从句中作told的宾语，可省。）他昨天告诉我的消息是真的。2.一些表示“建议、命令、要求”的名词后所跟的同位语从句中，谓语动词用虚拟语气should+动词原形表示。should可省。如：This is our only request that this （should）be settled as soon as possible.这就是我们唯一的请求：尽快解决这个问题。5）定语从句定语从句及相关术语 1.定语从句：定语从句是由关系代词或关系副词引导的从

25、句，其作用是作定语修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句，一般紧跟在它所修饰的先行词后面。2.关系词：引导定语从句的关联词称为关系词，关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as等；关系副词有where, when, why等。关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。注：关系代词有主语.宾语之分。一般whom作为宾语。4.定语：定语用来限定、修饰名词或代词的，是对名词或代词起修饰、限定作用的词、短语或句子，汉语中常用的表示。主要由形容词担任。此外，名词，代词，数词，分

26、词，副词，不定式以及介词短语也可以来担任，也可以由一个句子来担任单词作定语时通常放在它所修饰的词之前，作前置定语。短语和从句作定语时则放在所修饰的词之后，作后置定语。限定性定语从句一、关系代词（在句中作主语、宾语或定语）1. that既可代表事物也可代表人，which代表事物；它们在从句中作主语或宾语，that在从句中作宾语时常可省略关系词，which在从句中作宾语也可以省略。eg：this is the book （which）you want。而且，如果which在从句中作“不及物动词介词”的介词的宾语，注意介词不要丢掉，而且介词总是放在关系代词which的前边，但有的则放在它原来的位置

27、2. which作宾语时，根据先行词与定语从句之间的语义关系，先行词与which之间的介词不能丢3. 代表物时多用which，但在带有下列词的句子中用that而不用which，这些词包括当先行词是anything, everything, nothing , none等不定代词时，或者是由every, any, all, some, no, little, few, much等修饰时等，这时的that常被省略 还有先行词前有序数词或形容词最高级修饰时,或先行词就是序数词或最高级时.以及先行词中既有人又有物时.还有句中前面有which时,都只能用that4. who和whom引导的从句用来修饰人

28、，分别作从句中的主语和宾语，whom作宾语时，要注意它可以作动词的宾语也可以作介词的宾语 5. whose是关系代词，修饰名词作定语，相当于所修饰成分的前置所有格.它引导的从句可以修饰人和物, 当它引导的从句修饰物体时, 可以与 of which 调换,表达的意思一样。二、关系副词（在句中作状语）关系副词=介词+关系代词why=for whichwhere=in/ at/ on/ . which (介词同先行词搭配)when=during/ on/ in/ . which (介词同先行词搭配)1. where是关系副词，用来表示地点的定语从句。2. when引导定语从句表示时间注值得一提的是，

29、表示时间“time"一词的定语从句只用when引导，有时不用任何关系代词，当然也不用that引导。 By the time you arrive in London, we will have stayed there for two weeks. I still remember the first time I met her. Each time he goes to business trip, he brings a lot of living necessities, such as towels, soap, toothbrush etc。3. 当从句的逻辑主语是som

30、e, any, no, somebody, anybody, nobody, something, anything, everything或nothing时，常用there is来引导There is somebody here who wants to speak to you. 这里有人要和你说话。非限定性定语从句非限定性定语从句的作用是对所修饰的成分作进一步说明，通常是引导词和先行词之间用逗号隔开，将从句拿掉后其他部分仍可成立 1. which引导的非限定性定语从句来说明前面整个句子的情况或主句的某一部分 2.当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性

31、的，例如：Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了，他曾经是我的老师。My house, which I bought last year, has got a lovely garden.我去年买的的那幢房子带着个漂亮的花园。 This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。3.非限制性定语从句还能将整个主句作为先行词, 对其进行修饰, 这时从句谓语动词要用第三人称单数，例如

32、：He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这使我心烦。Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。4. 有时as也可用作关系代词5. 在非限定性定语从句中，不能用关系副词why和关系代词that，而用who, whom代表人，用which,whose代表事物.；关系代词引导的定语从句1.who指人在从句中做主语(1) The boys who are playing foo

33、tball are from Class One.(2) Yesterday I helped an old man who lost his way.2. whom指人，在定语从句中充当宾语，常可省略。（注：who和whom已无太大区别，可以通用。）(1) Mr. Liu is the person (whom) you talked about on the bus.(2) Mr. Ling is just the boy whom I want to see.(3) The man who/whom you met just now is my friend.注意：关系代词whom在口语

34、和非正式语体中常用who代替，可省略。如果在从句中做宾语,就用whom或who.比如: He is the man whom/who I talk to. 如果是在从句中作主语就只能用who.比如: He is the man who has an English book.3.which指物，在定语从句中做主语或宾语，做宾语时可省略(1) Football is a game which is liked by most boys.(2) This is the pen (which) he bought yesterday. 4. that指人时，相当于who或者whom；指物时，相当于w

35、hich。在定语从句中做主语或者宾语，做宾语时可省略。(1) The number of the people that/who come to visit the city each year rises one million.(2) Where is the man that/whom I saw this morning?5. whose通常指人，也可指物，在定语从句中做定语(1) He has a friend whose father is a doctor.(2) I once lived in a house whose roof has fallen in.whose指物时，

36、常用以下结构来代替(3) The classroom whose door is broken will soon be repaired.(4) The classroom the door of which is broken will soon be repaired.(5) Do you like the book whose color is yellow?(6) Do you like the book the color of which is yellow?注意介词+关系代词引导的定语从句关系代词在定语从句中做介词宾语时从句常由介词+关系代词引导(1) The school (

37、that/which) he once studied in is very famous.(2) The school in which he once studied is very famous.(3) Tomorrow I will bring here a magazine (that/which) you asked for.(4) Tomorrow I will bring here a magazine for which you asked.(5) Well go to hear the famous singer (whom/that/who)或主句的某一部分 2.当先行词

38、是专有名词或物主代词和指示代词所修饰时，其后的定语从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，他曾经是我的老师。My house, which I bought last year, has got a lovely garden.我去年买的的那幢房子带着个漂亮的花园。 This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。3.非限制性定语从句还能将整个主句

39、作为先行词, 对其进行修饰, 这时从句谓语动词要用第三人称单数，例如：He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这使我心烦。Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。4. 有时as也可用作关系代词5. 在非限定性定语从句中，不能用关系副词why和关系代词that，而用who, whom代表人，用which,whose代表事物.；关系代词引导的定语从句1.who指人在从句中做

40、主语(1) The boys who are playing football are from Class One.(2) Yesterday I helped an old man who lost his way.2. whom指人，在定语从句中充当宾语，常可省略。（注：who和whom已无太大区别，可以通用。）(1) Mr. Liu is the person (whom) you talked about on the bus.(2) Mr. Ling is just the boy whom I want to see.(3) The man who/whom you met ju

41、st now is my friend.注意：关系代词whom在口语和非正式语体中常用who代替，可省略。如果在从句中做宾语,就用whom或who.比如: He is the man whom/who I talk to. 如果是在从句中作主语就只能用who.比如: He is the man who has an English book.3.which指物，在定语从句中做主语或宾语，做宾语时可省略(1) Football is a game which is liked by most boys.(2) This is the pen (which) he bought yesterday

42、. 4. that指人时，相当于who或者whom；指物时，相当于which。在定语从句中做主语或者宾语，做宾语时可省略。(1) The number of the people that/who come to visit the city each year rises one million.(2) Where is the man that/whom I saw this morning?5. whose通常指人，也可指物，在定语从句中做定语(1) He has a friend whose father is a doctor.(2) I once lived in a house

43、whose roof has fallen in.whose指物时，常用以下结构来代替(3) The classroom whose door is broken will soon be repaired.(4) The classroom the door of which is broken will soon be repaired.(5) Do you like the book whose color is yellow?(6) Do you like the book the color of which is yellow?注意介词+关系代词引导的定语从句关系代词在定语从句中做

44、介词宾语时从句常由介词+关系代词引导(1) The school (that/which) he once studied in is very famous.(2) The school in which he once studied is very famous.(3) Tomorrow I will bring here a magazine (that/which) you asked for.(4) Tomorrow I will bring here a magazine for which you asked.(5) Well go to hear the famous sin

45、ger (whom/that/who)宾、定、状)，也能正确选择出关系代词/关系副词。例1. Is this museum _ you visited a few days ago?A. whereB. thatC. on whichD. the one例2. Is this the museum _ the exhibition was held?A. whereB. thatC. on whichD. the one答案：例1 D，例2 A例1变为肯定句： This museum is _ you visited a few days ago.例2变为肯定句： This is the mu

46、seum _ the exhibition was held. 在句1中，is后应跟表语，只有the one可以，而后面的you visited a few days ago则做one的定语从句。而句2中, 主、谓、宾俱全，从句部分为句子的状语表地点，既可用副词where，又因 in the museum词组，可用介词in + which 引导地点状语。而此题中，介词on 用的不对，所以选A。关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选择关系代词 (who, whom, that, which, whose)； 先行词在从句中做状语时，应选择关系副词 ( where

47、地点状语，when 时间状语，why 原因状语)介词+关系词1）介词后面的关系词不能省略。2）that前不能有介词。3） 某些在从句中充当时间，地点或原因状语的"介词+关系词"结构可以同关系副词when ,where和why 互换。This is the house in which I lived two years ago.This is the house where I lived two years ago.Do you remember the day on which you joined our club?Do you remember the day wh

48、en you joined our club? This is the reason why he came late. This is the reason for which he came late.（八）先行词和关系词二合一1)Whoever spits 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) （九）as,whic

49、h引导的非限定性定语从句由as, which 引导的非限定性定语从句，as和which可代整个主句，相当于and this或and that。As一般放在句首，which在句中。As we know, smoking is harmful to one's health. The sun heats the earth, which is very important to us.典型例题1）Alice received an invitation from her boss, _came as a surprise. A. it B. that C. whichD. he 答案C.

50、此为非限定性从句，不能用 that修饰，而用which.，it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。况且选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，用于非限定性定语从句，而what不可。That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。3）It rained hard yesterday, _ prevented me

51、 from going to the park. A. thatB. whichC. as D. it答案B. as 和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。但不同之处主要有两点：(1） as 引导的定语从句可置于句首，而which不可。(2） as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。 在本题中，prevent由于是行为动词，所以正确选项应为B。As 的用法例1. the same as；suchas 中的as 是一种固定结构, 和一样。I

52、have got into the same trouble as he (has).例2. as可引导非限制性从句，常带有'正如'。As we know, smoking is harmful to one's health.As is known, smoking is harmful to one's health.As是关系代词。例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。 一、“as / which” 特殊定语从句的先行成分1. 形容词或形容词短语作先行成分, 具有形容词意义的介词短语也可以充当先行成分，如：My

53、 grandmothers house was always of great importance to me, as my own is.在一定的语言环境里，有些名词可以具有形容词的性质。这些名词主要是那些表示人的身份、职业、状态的名词。值得一提的是，在这些具有形容词性质的名词之后，引导定语从句的关系代词不能用who / whom.2. 动词短语先行成分这种动词短语既可是限定形式也可是非限定形式。如果是动态动词短语，它们在从句中就一般有限定或非限定形式的替代动词do和as / which一起代替。do可以出现，也可以不出现，但不能用其它动词代替。3. 句子作先行成分这句子可以是整个主句也可

54、以只是主句中的一个从句。有时是连续几个句子，有时甚至可以是一个完整的故事。二、“as/which”特殊定语从句在句中的位置由于先行成分的构成成分不同，“as/which”特殊定语从句在句中的位置有以下几种情况：1. 形容词做先行成分时：形容词或形容词短语（含具有形容词性质的名词）作先行成分，“as / which”特殊定语从句置于先行成分之后。2. 动词短语作先行成分时：动词短语作先行成分时，“as / which”特殊定语从句置于先行成分之后。但是，当从句中含有表示主观意志的插入成分时，“as”特殊定语从句可以移至句子之首。3. 句子作先行成分时：“as”特殊定语从句的位置较灵活，可以置于先

55、行成分之前、之中或之后。但如果先行成分是直接引语，“as”特殊定语从句多在先行成分之前。如果先行成分是否定句，“as”特殊定语从句与否定词的相对位置不同可以使它产生不同的意义。由于“as”特殊定语从句具有这一特点，所以有时它的位置不能随便移动。在非正式的文体里，“which”特殊定语从句可以出现在先行成分之中。三、“as/which”特殊定语从句的语义功能一般说来，as与which的语义功能相同，可以相互替换。但先行成分为句子时，它们的语义功能则有差异。1. 表示结果表示结果的特殊定语从句与其先行成分之间存在着一定的因果关系，从句中往往使用有结果意义的词，如动词result, make, enable, cause和形容词interesting, surprising, delightful, disgraceful等。2. 表示评注表示评注的特殊定语从句对其先行成分所述事实的正确性有肯定的倾向，它通常与那些表示客观事实，普遍真理或某种习性的先行成分连用；从句中则常用一些表示“合乎自然规律”“众所周知”或“经常发生”等意义的词语，如natural, known to all, usual等。3. 有无状语意义 “as”特殊定语从句具有状语意义（主要是方式状语意义），而“which”特殊定语从句则无状语意义。“as”特殊定语从句的状语意义要求它在语义上与其先行