今天给大家整理了与高中英语从句的相关语法知识,非常全面,从句一直是很多同学做完型和阅读题型的老大难问题,配合例题来给大家梳理梳理。
从句的基础概念
由一个主句和一个或一个以上从句构成的句子叫做复合句。所谓主句,就是在复合句中起统领作用的句子,它是全句的主体,通常可以独立存在;而从句则是复合句的一个句子成分,不能独立存在。
如:You’ll feel betterafteryou take the pills. 吃完药丸后你会感到好一些。
主句是You’ll feel better,从句是after you take the pills,由after引导,在整个复合句中用作状语,表示时间。
注意,英语的复合句不是简单句的反面,不要将它误解为“复杂句”。事实上,英语的简单句有时也可以比较“复杂”,而复合句也可以比较“简单”。
如:He stopped because he was tired. 他停下来是因为他累了。
这个句子比较“简单”,却是一个典型的复合句,其中的he stopped是主句,because he was tired是从句,在复合句中用作状语,表示原因。
从句的分类
一般说来,一个从句在复合句充当什么成分我们就叫它为什么从句——从句在复合句用作主语,我们就叫它为主语从句;从句在复合句用作宾语,我们就叫它为宾语从句等。
如:
He answered that he knew nothing about it. 他回答说他不知情。
that 引导的从句在复合句中用作动词answered的宾语,因此为宾语从句。
The trouble is that I have lost his address. 麻烦的是我把他的地址丢了。
be动词后做表语从句
He was rather pleased when he won that prize. 他获奖后相当高兴。
用状语表时间,也叫时间状语从句。
名词性从句
(主语从句、表语从句、宾语从句、同位语从句)
主语从句、表语从句、宾语从句和同位语从句在复合句中的充当的成分和其名称相同,分别作主句的主语、表语、宾语和同位语。上述这四种从句均被称为名词性从句。
所有的名词性从句均不能用逗号分开,并且它们都用相同的关联词,关联词如下:
① 主从连词:that (无意义), whether (是否), if (是否)(在句子中不充当任何成分)
② 连接代词:who (谁), whom (谁), whose (谁的), what (什么), which (哪一个)
③ 连接副词:when (什么时候), where (什么地方), how (怎样), why (为什么)
主从连词只起连接作用,连接代词和连接副词除了起连接作用外,还充当从句某一个成分。另外,可以用whatever, whichever, whoever, who(m)ever等连接代词引导名词性从句,来加强语气。
(一)主语从句(subject clause)
在主句中用作主语的主谓结构称之为主语从句。
That he will come to the discussion is certain.他来参加讨论是确定的。
When the meeting is to be held has not yet been decide. 会议什么时候召开还没有决定。
主语从句放在句首,句子常常显得比较笨重,因此通常可以把it放在句首,作形式主语,而将主语从句放在后面。例如上面的句子可以分别改写为:
It is certain that he will come to the discussion.
It has not yet been decide when the meeting is to be held.
(二)宾语从句(object clause)
在主句中作谓语动词、介词及非谓语动词的宾语的主谓结构称之为宾语从句。
在引导宾语从句时,从属连词that在口语中和非正式文本中常省略。
(1)动词后的宾语从句
Weknowthat a parrot can’t really speak.我们知道鹦鹉不会真的说话。
Hewants to tellus what he thinks.他想告诉我们他所想的事情。
The club willgivewhoever wins a prize. 获胜者俱乐部将颁奖。
(2)形容词的宾语从句
有些形容词可以用that引导宾语从句,表示说话人对某一事物的态度并带有感情色彩。
常见的这类形容词有:
afraid, amazed, astonished, aware, certain, confident, delighted, glad, grateful, happy, proud, sad, sorry, sure, surprised等。
例如:
I am glad that you have come. 你来了,我真高兴。
I am afraid that you are wrong on this point.恐怕你在这点上是错误的。
(三)表语从句(predicative clause)
在主句中担当表语的主谓结构称之为表语从句。
One idea is that fish is the best brain food.有一种看法认为鱼是最好的补脑食品。
The problem is where we can hold our meeting.问题是我们可以在哪儿举行会议。
That is what he really wants.那就是他真想要的东西。
(四)同位语从句(常考)
同位语从句用于对前面出现的名词作进一步说明,一般用连词that引导,由于先行名词的意义不同,也可用whether,who,when,where,what,why,how等引导。
常见的先行名词有:
fact,idea,belief,news,hope,conclusion,evidence,suggestion,order,problem,report,decision.有时由于谓语较短,将同位语从句位于谓语之后。
如:
She finally made the decision that she would join the fashion show.
The news came that their team had won the championship.
名词性从句常考易错点
1.that 引导主语从句时,that 没有意义,但不能省略。
2.从句作主语时,多数情况下由 it 作形式主语,而把主语从句放在后面,尤其是谓语部分(包括宾语)较短的情况下。
3.whether 既可以引导主语从句也可以引导宾语从句,但if不能引导主语从句。whether 后面可以加or not, 而if 不能与or not 连用。
作介词宾语时不用if.如:
①Whether I knew John doesn’t matter. = It doesn’t matter whether I knew John.
我是否认识约翰没有关系。②Whether or not she’ll come isn’t clear. = Whether she’ll come or not isn’t clear. = It isn’t clear whether …. 她是否来还不清楚。
定语从句
定语从句的简化规律
(一)改用“不定式”或“不定式短语”
如果定语从句的时态与主句的时态具有同时性(包括谓语有情态动词)或之后性,则可以用“关系代词或关系副词+不定式”来简化,或直接用“不定式”来修饰先行词。
例1:
We moved to the country so that the children would have a garden in which they could play in.我们搬到了乡下,好让孩子们有个花园在里面玩。
改为:
We moved to the country so that the children would have a garden in which to play.
或者:
We moved to the country so that the children would have a garden to play in.
(二)改用“介词短语”
介词短语替代定语从句有两种方式:(1)省略“关系副词+主语+be动词”,或“关系代词+be动词”;(2)根据从句的意思改编。
例1:
We have never forgotten the days (when we were) at college.
我们从来没有忘记在大学对书的日子。
例2:
I don’t know the person (who is) in your office.
在你办公司的那个人我不认识。
(三)改用“现在分词短语”和“过去分词短语”
例1:
Anyone touching that wire will get an electric stock.
任何人碰到那根电线就会触电。
= Anyone who touches that wire will get an electric stock.
例:
Charles and Sydney, looking (=who look)so much like each other, are often considered to be twins.
查尔斯和悉尼两个人的相貌非常相似,经常被人误解为双胞胎。
定语从句常考易错点
1)当先行词是
all,anything,everything,something,nothing等不定代词或先行词前有first,last,any,few,much,some,no,only以及形容词最高级修饰时,只能用关系代词that引导从句。
如:That is all that I've heard from him.
He's the first person that I'm going to interview this afternoon.
2)关系代词的省略
在从句中作宾语的关系代词常可省略。关系代词紧跟介词,作介词宾语时不可用that,只可用which或whom引导从句,并且不可省略,但当介词位于宾语从句句末时,作为介词宾语的关系代词仍可用that,也可省略。
如:
This is one of those things with which we have to put up.
This is one of those things (whichthat) we have to put up with.
3)引导定语从句的关系副词有when,where,why等。关系副词在从句中作状语,意义上相当于一个“介词+which”的结构。
如:
Even in comic books where(=in which) there are no words,the stories are fully expressed through the drawings.
No one knows the reason why(=for which) he was so angry that day.
状语从句
地点状语从句:引导地点状语从句的连词是where,wherever.
Wherever she went,she took her little daughter with her.
原因、结果和目的状语从句:
1)引导原因状语从句的从属连词有:because,as,since,now(that),seeing that,considering that,in that等。
Considering that he is a freshman,we must say he is doing well.
2)引导结果状语从句的连词有:so...that,such...that
,so that,that,so等。
Mickey Mouse is so attractive that the children are reluctant to leave.
3)引导目的状语从句的连词有:so that,in order that,for fear that,lest等,从句常使用may,might,can,could,would等情态动词。
We got up early this morning so that we could catch the first bus to the railway station.
条件和让步状语从句:
1)引导条件状语从句的连词和词组有if,unless,as(so) long as,on condition that,in case,provided(providing) that,supposing等。
As long as you have the right equipment,you can use a telephone line to transmit computer data.
2)引导让步状语从句的连词和词组有though,although,whether,even though,even if,no matter what(when,how...),whatever(whenever,wherever,however....)等。though,even if等引导状语从句可转换成含有as的部分倒装结构,具有强调意义。其结构为“形容词(副词、动词、名词)+as+主语+谓语”。
No matter what you may say,I would not change my mind.
Young as he is,he is quite experienced in this work.(=though he is young)
时间状语从句:
引导时间状语从句的从属连词和词组有:
1)when,whenever,while,as,after,before,since,till,until,once等。
We have learnt quite a lot about it since we came here.
2)as soon as,hardly(scarcely)...when,no sooner...than,each(every) time,the moment,immediately(that)等。
As soon as I sent an e-mail message,I received positive responses.
The moment he heard the good news,he jumped with joy.
从句的两大特点
1.从句引导词
英语中的从句有个特点,就是通常要用一个词来“引导”,这个词我们就称它为“引导词”。不同的从句往往需要不同的引导词来引导,即使同一个词可用于引导多种从句,那它的用法和意思有所相同,如when可用于引导主语从句、表语从句、宾语从句等,它的意思是“什么时候”。
如:
When he will come is still unknown. 他什么时候来还不知道。
The question is when he did it. 问题是他什么时候干了此事。
I don’t know when the meeting will start. 我不知道会议什么时候开始。
when还可以引导时间状语从句,它的意思是“当……的时候”。
英语中用于引导从句的引导词何时省略与何时保留是有规律的,要遵循英语习惯,不可随意省略,否则会导致语法错误。
2. 从句词序
英语中的从句,无论是主语从句还是宾语从句,是定语从句还是状语从句,它都总是使用陈述句词序,也就是采用“主语+谓语+其他成分”这样的词序。
但是,当一个从句由what, who, whose, when, where, why等这样的“疑问词”来引导时,有的人可能会在从句中误用疑问句词序,这是一个常见的错误。
如:
他什么时候离开,现在还不知道。
误:When will he leave is not known yet.
正:When he will leave is not known yet.
析:when在此引导主语从句,要用陈述句词序,不能用疑问句词序。
我记不起他是什么样子了。
误:I don’t remember what did he look like.
正:I don’t remember what he looked like.
析:what在此引导宾语从句,要用陈述句词序。
常考语法点“主将从现”
主将从现是一种出现在状语从句中的语法现象,多指在时间状语从句和条件状语从句中,当主句是一般将来时态,则从句要用一般现在时替代一般将来时。
因为主将从现出现在状语从句中,在这里我们就以状语从句的几个类别为根据来列举主将从现的标志性词语。
时间状语从句
when, whenever, since, till, once, as soon as, while, as, before, after
如:I will be a math teacher when I grow up.
条件状语从句
if, unless, as(so)long as
如:If I have extra money, I will pay the bill for you.
原因状语从句
because, since, as, for, now that
如:The tutor will leave here now that you have no problems.
让步状语从句
though, although, even if, even though, however
如:Though you have advantages in this match, I will not give up.
目的状语从句
in order that, so that, that
如:In order that Lily can get the prize, we will have a planin detail.
在条件状语从句中,如果主语是一般将来时,从句要用一般现在时。
一个句子的中心意思体现在主句中,所以判断是否使用主将从现首先要做的是区分主从句。当找到主句,分析其时态为一般将来时或借助某些结构表达将来含义时,则从句使用一般现在时态。