【导语】⾼中英语的⼀⼤难点就是各种从句，很多同学头疼的地⽅，仔细看完，⽂章给⼤家有详细的举例，认真理解，对是⾮常有帮助的。以下内容由整理发布，欢迎阅读参考！更多相关讯息请关注！
英语基础概念：主句+从句=复合句
1. 有关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 better after you take the pills. 吃完药丸后你会感到好⼀些。The police learned that he wasn’t there at that time. 警察获知他那时不在场。
这两句都是复合句，第⼀句的主句是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；第⼆句的主句是The police learned是主句，that he wasn’t there at that time是从句，由that引导，在整个复合句中⽤作宾语。
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 becau 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，becau he was tired是
从句，在复合句中⽤作状语，表⽰原因。2. 从句的分类前⾯我们说到从句是整个复合句的⼀个句⼦成分，它可以⽤作主语、宾语、定语、状语等。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；从句在复合句⽤作状语，我们就叫它为状语从句；等等。
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如：He answered that he knew nothing about it. 他回答说他不知情。The trouble is that I have lost his address. ⿇烦的是我把他的地址丢了。He was rather plead when he won that prize. 他获奖后相当⾼兴。She was not in the train that arrived just now. 她不在刚到的那列车上。
第⼀句中的that he knew nothing about it为宾语从句，因为它在复合句中⽤作动词answered的宾语；第⼆句中的that I have lost his address为表语从句，因为它在复合句中⽤在连系动词is后作表语；第三句中的when he won that prize为状语从句，因为它在复合句中⽤状语，表⽰时间，所以也叫时间状语从句；第四句中的that arrived just now为定语从句，因为它在复合句中⽤作定语，修饰名词the train。判断关系代词与关系副词⽅法⼀：⽤关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后⾯⽆宾语，就必须要求⽤关系代词；⽽不及物动词则要求⽤关系副词。例如：
冬天的散文This is the mountain village where I stayed last year.
I'll never forget the days when I worked together with you.判断改错（注：先显⽰题，再显⽰答案，横
线；⽤不同的颜⾊表⽰出。）（错） This is the mountain village where I visited last year.（错） I will never forget the days when I spent in the countryside.（对） This is the mountain village (which) I visited last year.（对） I'll never forget the days (which) I spent in the countryside.习惯上总把表地点或时间的名词与关系副词 where, when联系在⼀起。此两题错在关系词的误⽤上。⽅法⼆：准确判断先⾏词在定语从句中的成分(主、谓、宾、定、状)，也能正确选择出关系代词/关系副词。
例1. Is this muum ___ you visited a few days age?
A. where
B. that
C. on which
D. the one
例2. Is this the muum ____ the exhibition was held.A. where B. that C. on which D. the one
答案：例1 D，例2 A例1变为肯定句：
This muum is ___ you visited a few days ago.
例2变为肯定句：
This is the muum ___ the exhibition was held.
在句1中，所缺部分为宾语，⽽where, that, on which都不能起到宾语的作⽤，只有the one既做了主句的表语，⼜可做从句的宾语，可以省略关系代词，所以应选D。
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 muum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。钓草鱼配方
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, who)；先⾏词在从句中做状语时，应选择关系副词 ( where 地点状语，when 时间状语，why 原因状语) 。语法⼩知识：主将从现的标志词
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 p
ay the bill for you.原因状语从句becau, 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。1.⽤“连词＋分词”来替代从句当主句和从句的主语⼀致，谓语的时态⼜是同时段发⽣，可以把从句的主语省去，变谓语动词为现在分词或过去分词。如果分词的逻辑或时间意义不明确，还可以保留连词。
Guests mingle while enjoying cake, punch and other treats.客⼈们⼀边吃蛋糕、喝饮料以及享⽤其它的⾷品，⼀边却在⼀起聊天。
While speaking out against Hitler’s atrocities, the American people generally favored isolationist policies and neutrality. 虽然美国⼈谴责希特勒的暴⾏，但是他们却⼀惯奉⾏孤⽴政策和中⽴态度。
Plastics are materials which are softened by heat and t into lasting form when shaped in a mold.注：如果从句的谓语是系动词be，在简化句型时应该把be动词改成being，但是由于being语义意义，
所以可以省略，这样就造成了形容词作状语了。The apples, when ripe, are picked. 这些苹果⼀旦熟了就要被摘下来。
She knows all the hazards of smoking while pregnant. 她知道怀孕时吸烟的⼀切危害性。
2. ⽤“介词＋分词”来替代从句⼀般说来，⽤on和at表⽰“as soon as, once”。on后⾯常接“来、去”之类的词，at后⾯常接“听到、看到”之类的词。in后⾯接其他带动作的词，相对于从属连词“while”。
On removing them he was stunned to e that the plates were fogged where the crystals had covered them. 当他把晶体揭开时，发现盘⼦上⽅雾蒙蒙，他吃了⼀惊。
In running down the stairs, I heard the clock struck twelve.我在跑下楼的时候，听见钟敲了⼗⼆下。
He jumped with joy at hearing the news. 他⼀听到这个消息就⾼兴得跳了起来。
3. ⽤“介词＋动作性名词”来替代从句同上⾯⼀样，At基本上后接sound，sight“听到、看到”之类的词；on接“回来、到达”之类的词；⽤in，during表⽰“when, while”；⽤over表⽰“while”之意。当然，这⼀切都是相对的分类。
The little girl pasd out at sight of a snake. ⼩⼥孩⼀看到蛇就昏过去了。
In our hurry to get from one place to another, we failed to e anything on the way. 当我们急急忙忙从这⼉到那⼉的时候，⼀路上什么也没有看见。
On arrival at the railway station, he found the train had already left. 当他到达⽕车站的时候，他发现⽕车已经开⾛了。
He had intended to go, but on cond thoughts, he gave up the idea.他本来想去，但进⼀步考虑后，打消了这个念头。During my abnce, would you plea take care of my cat?在我不在的时候，请帮我照看⼀下猫，好吗？
He fell asleep over a book. 他看书的时候睡着了。
After reelection he announces that he will not help. 经过⼀番考虑后，他宣布将不提供任何帮助。
After graduation, he went to America for his PhD studies.毕业之后，他去了美国攻读博⼠。
4. ⽤“并列句”代替
Two other pos were tried and I emerged from the booth to find a lot people waiting for my signatures.⼜试了两个其他的姿势后，我从拍照亭⾥出来，发现很多⼈在那⾥等待我的签名。
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), who (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 clau）在主句中⽤作主语的主谓结构称之为主语从句。例如：That he will come to the discussion is certain.他来参加讨论是确定的。
That the moon moves round the earth is well known to all of us.⽉球绕地球转动，这是我们⼤家都熟知的。
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 is well known to al
l of us that the moon moves round the earth.It has not yet been decide when the meeting is to be held.下⾯再举⼀些例句：What they are after is profit.他们追求的是利润。
动机与人格That he is still alive is sheer luck.他还活着全靠运⽓。
Who did the work is unknown.谁⼲了这⼯作⽆⼈知道。
Whether she will join us won’t make too much difference.It won’t make too much difference whether she will join us.她是否参与我们的活动⽆关紧要。
Which way is more effective is still a question.It is still a question which way is more effective. 哪种办法效率更⾼还是个问题。
怀孕吃芒果好吗（⼆）宾语从句（object clau）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
We know that a parrot can’t really speak.我们知道鹦鹉不会真的说话。
He wants to tell us what he thinks.他想告诉我们他所想的事情。
Knowing that it was going to rain, they decided to work inside the hou.
知道要下⾬了，于是他们决定在室内⼯作。(现在分词knowing的宾语从句)
I want to know whether/if you still work in the factory.
我想知道你是否还在⼯⼚⼯作。（不定式to know的宾语从句）
The club will give whoever wins a prize. 获胜者俱乐部将颁奖。
Up to now we can’t say whether his theory can stand the test.
到⽬前为⽌我们还不能说他的理论是否经得住考验。
（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, surprid等。
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。He is quite confident that he will pass the examination.他很有信⼼通过这个考试。
（三）表语从句（predicative clau）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。
My question is how information is stored in the long-term memory.我的问题是信息是怎样储存在长期记忆中的。
That is what he really wants.那就是他真想要的东西。
我是一只猫
It ems that everything goes smoothly.似乎⼀切都进⾏得很顺利。
江东是哪里
鸟语花香的意思（四）同位语从句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
