用6个维度去区分初中英语3种从句（真正学会无难事）
初中英语里有三大从句，它们分别是状语从句、宾语从句和定语从句。我们首先应该弄懂什么叫从句，从句是复合句中具有分属地位的一种分句，是把整个句子当作复合句中的一个成分来用，整个从句在复合句中的作用就相当于一个词、一个短语。从句本身就是一个句子，有从句本身的主语和谓语动词，从句前面要有一个引导词或连词，把整个从句“统领”起来，当然有时这个引导词或连词可省略，在“暗中统领”着从句。
我们来认识一下
Where did you study beforeyou came to this school?
上面这个句子，既有主句Where did you study，又有从句before you came to this school,包含主句、从句的句子就叫复合句。before是从句的引导词，后面一个you 是从句的主语，came是从句的谓语动词。整个从句before you came to this school的作用就相当于last year或two years ago这样的词或短语，表示主句动作发生的时间。
在复合句中充当状语的从句叫状语从句，充当宾语的从句叫宾语从句，充当定语的从句叫定语从句。
关于这三种从句，是初中英语学习中的难点，相当一部分学生是无法完全突破的，同时也是重点，是很常考的考点，几乎每个省市的中考题中都有它们的影子。很多学生反映没办法弄懂，心里害怕含有从句的长句，不能正确理解、运用它们。下面，我试图从六个维度出发，来跟大家探讨一下这三大从句：
一、从句的位置
理解含有从句的长句，首先一种能力是你要能够看出它是什么从句。要达到一眼就能看出是什么从句的程度，就必须了解从句的位置和从句的含义、作用。状语从句可位于主句之后也可位于主句之前，用逗号隔开。如：
I was watching TV when he came in last night.
=When he came in last night,I was watching TV.
宾语从句位于动词或介词之后作宾语，具体有下列几种情况：
1）位于及物动词（vt.）之后；
2）位于及物动词（vt.）+sb之后；
3）位于介词（prep.）之后；
4）位于连系动词+形容词（adj.）之后；
5）位于say/explain to sb之后。
1. I think（that）you are right.
2. He told mewhere he would go for vacation.
3. This book is abouthow we can learn English well.
4. I am afraid (that) he isn’t here at the moment.
5. He said to me that he had been to Beijing twice.
定语从句位于名词或代词（叫先行词）之后，不过有时候在先行词与定语从句之间可插入副词或介词短语等。
1. Do you know the man(先行词）（who/whom/that）our head teacher is talking to?
2. Is there anything(先行词）(that)I can do for you?
3. Do you still remember the teacher(先行词）in that school who/that taught us math when we were in Grade 6?
二、从句的含义、作用
了解了从句的位置，基本上就能帮助我们判断这个从句是什么从句，但也有特殊情况，大家来判断一下下面两句中分别包含了什么从句：
1. The teacher had a talk with the studentthat failed the exam this time.
2. The teacher told the studentthat he should study harder.
如果不把握好从句的含义、作用，只是根据从句的位置判断从句的类型，很可能就会出现错误。上面两句中从句都是位于名词the student后面，但第一句才是定语从句，从句中所表示的是对其前面的名词the student进行修饰限定。而第二句是宾语从句，从句中所表示的是主句谓语动词told的内容，the student是间接宾语，而宾语从句作told的直接宾语。
所以，在理解三种从句时一定要注意从句的作用：状语从句在复合句中作状语，对主句的动词、形容词、副词加以修饰;宾语从句在复合句中作主句动词或介词的宾语，表示主句动词或介词的具体内容;定语从句作定语，对前面的名词或代词（即先行词）加以修饰限定。
三、从句的引导词
懂得了是什么从句，我们就较容易选出合适的引导词来“统领”这个从句。当然，我们还必须知道这三种从句分别有哪些引导词。状语从句有九种，它们的引导词分别是：
1）引导时间状语从句的有：when/while/as/before/after/till/until/as soon as/since/once/every time/next time/the first time/the last time/by the time。
2）引导原因状语从句的有：because/as/since/now that。
3）引导条件状语从句的有：if/unless/as long as。
4）引导比较状语从句的有：than/as...as。
5）引导方式状语从句的有：as/as if/as though。
6）引导地点状语从句的有：where /wherever。
7）引导让步状语从句的有：though/although/even if/even though/whenever=no matter when/whatever=no matter what/whoever=no matter who/however=no matter how/whether...or...。
8）引导目的状语从句的有：so that/in order that。
9）引导结果状语从句的有：so...that.../such...that...。
状语从句的引导词在状语从句中不充当任何成分，只是起着引导从句的作用。
选择状语从句的引导词主要根据主句、从句的意思来确定。
宾语从句的引导词有三类：
一）连词that(当把陈述句用作宾语从句时，用that引导，that在宾语从句中不充当成分，可省略）。如：
1. 把直接引语改为间接引语
He said to me,“I will go to the museum tomorrow”.
He told me that he would go to the museum the next day.
2. 合并成复合句
I’m sure. Maria can pass the exam this time.
I’m sure that Maria can pass the exam this time.
二）连词if/whether（当把一般疑问句用作宾语从句时，用if或whether引导，if/whether在宾语从句中不充当成分，但不能省略）。
1.把直接引语改为间接引语
He said to me,“Are you interested in English?”
He asked me if/whether I was interested in English.
2.合并成复合句
Do you know? Does she like Beijing Opera?
Do you know if/whether she likes Beijing Opera?
注意: 一般情况下,if 和 whether 可以互换,但以下 3 种情况只能用 whether:
(1)与 or not 连用。 如:He asked me whether or not I was coming. 他问我是否要来。
(2)在介词之后。 如:It depends on whether it is going to rain. 这要看天气是否会下雨。
(3)在不定式之前。 如:We haven"t decided whether to go there. 我们还没有决定是否去那里。
三）连接代词或连接副词（当把特殊疑问句用作宾语从句时，用连接代词或连接副词引导,这里的连接代词、连接副词实际上就是特殊疑问句中的疑问代词、疑问副词，注意连接代词、连接副词在宾语从句中充当某一成分，不能省略）。如：
1. 把直接引语改为间接引语
He said to me,“where does Maria live?”
He asked me where Maria lived.
2. 合并成复合句
She asked. How many times has Jack been to Hong Kong?
She asked how many times Jack had been to Hong Kong.
选择宾语从句的引导词既要根据主句谓语动词的性质，也要根据宾语从句的意思（看看宾语从句是否缺少什么）。
当主句谓语动词为陈述性质（即肯定语气）如say/think/believe/suggest/advise/be sure/hope/wish等时，引导词用that;当主句谓语动词为疑问性质（即不肯定语气）如ask/wonder等时，引导词用if/whether/连接代词/连接副词。如：
1.I believethat he is right.
2.I am sure that he can pass the exam.
3.I am not surethat/if he can pass the exam.
4.I wonderwhere he lives.
5.I don’t know what I shall do（及物动词）next.
定语从句的引导词有两类：
一）关系代词
当先行词表示人时，引导词用who/that(在从句中作主语或宾语）/whom（在从句中只作宾语）/whose（在从句中作定语，后接名词）;
当先行词表示事物时，引导词用which/that(在从句中作主语或宾语）/whose(在从句中作定语，后接名词）。
1. Do you know the person who/that is standing under the tree?
2. I prefer the bookwhich/that you showed me just now.
3. Look at the building whose walls(名词）are yellow.
注意：1）what和how不能引导定语从句；
2）引导词在定语从句中作宾语时可省略，但引导词所代替的那个宾语应该去掉；
如：Do you know the man (who/that/whom)I talked to just now?
在talked to后面不能再来一个宾语him,因为已经用引导词who/that/whom代替him作talked to的宾语了。
3) 如果把介词提到引导词前面时，先行词表示人，引导词只用whom,先行词表示事物，引导词只用which,即人+介词+whom和事物+介词+which。如上面一句也可以表达成Do you know the man to whom I talked just now?
4) 先行词是 a way/the way/ways时,引导词可用that/in which或省略引导词。
5) 下列情况只能用 that (不用 which) 来指代物
(1)先行词为 all, much, little, something, anything, everything, nothing 等不定代词时。如:
I will do everything that I can do to help you. 我将做我能做的一切事情来帮助你。
(2)先行词是最高级或者被形容词的最高级修饰时。 如:
This is the most important task that should be finished soon. 这是必须马上完成的最重要的任务。
(3)先行词为数词或被序数词修饰时。 如:
You are the first men that like the kind of book. 你们是第一批喜欢这种书的人。
(4)先行词中既有人又有物时。 如:
We were deeply impressed by the teachers and schools that we had visited. 我们访问过的老师和学校给我们留下了很深的印象。
(5)当先行词前有 the one, the only, the last, the very, any, few, little, no, all 等词修饰时,引导词只能用
that。如:
He is the only person that knows the truth. 他是唯一知道真相的人。
(6)当主句中已经含有疑问词 who 或者 which 时,只用 that。 如:
Which is the bike that you lost? 哪一辆是你丢的自行车?
6) 下列情况只能用 who (不用 that) 来指代人
(1)先行词是 one, ones, anyone 时,适宜用 who。 如:
One who has nothing to fear dares to tell the truth. 一个无所畏惧的人敢于说实话。
Don"t tell anyone about the news who shouldn’t be told. 别告诉不该告诉的人任何消息。
(2)当 those 作先行词指人时,引导词只能用 who。 如:
Those who respect others are often respected by others. 尊敬别人的人也常常受人尊敬。
(3)当先行词有较长的后置定语时,适宜用 who。 如:
I met a foreigner in the street who could speak Chinese well. 我在街上遇到一位可以把中文说得很好的外
国人。
(4)有两个定语从句,其中一个关系代词已经使用了 that,另一个宜用 who。 如:
The boy that you met last night is her brother who can make kites. 你昨晚遇到的那个男孩是她的哥哥,他会制作风筝。
(5)在 there be 开头的句子中用 who。 如:
There is an old man who wants to see you. 有一个老人很想见你。
(6)当主语是 I, he, you, they 等时,常用于谚语、格言中,只能用 who。 如:
He who plays with fire gets burned. 玩火者自焚。
7) 非限制性定语从句不能用that引导。
二）关系副词（在定语从句中作状语）（高中阶段学习）
当先行词表示地点时，引导词用where;
当先行词表示时间时，引导词用when;
当先行词表示原因时，引导词用why。
选择定语从句的引导词既要根据先行词表示什么，也要根据引导词在定语从句中的作用来确定。试对比：
1. I still remember the school which/that（作从句谓语的宾语） I visited(及物动词）last year.
2. I still remember the school where（在从句中作状语） I taught（不及物动词） for ten years.
四、从句的语序
状语从句、宾语从句、定语从句都要用陈述句语序。
在状语从句中，因为引导词在从句中不充当成分，所以状语从句的构成是：引导词+主语+谓语动词+...。
宾语从句的构成有下列几种情况：
1）that/if/whether+主语+谓语动词+...
2）作主语的连接代词who/what/which+谓语动词+...
I want to know what made him so angry.
3）作宾语、状语、表语、宾补的连接代词或连接副词+主语+谓语动词+...
Can you tell me when you were born?
4）作主语的定语的连接代词whose/what/which/how many/how much+名词+谓语动词+...
The head teacher wonders whose fathers work in the hospital.
5）作非主语的定语的连接代词whose/what/which/how many/how much+名词+主语+谓语动词+...
The farmer wanted to know how many apples the boy had picked.
对于定语从句，因为引导词在从句中的作用不同，因此定语从句的构成也有几种情况：
1）作主语的引导词+谓语动词+...
Do you know the man who/that is talking to our English teacher?
2) 作主语的定语的引导词whose+名词+谓语动词+...
I know the man whose son studies in the famous university.
3) 作非主语的定语的引导词whose+名词+主语+谓语动词+...
I visited the man whose son I had lived with for three years yesterday.
4) 作宾语、状语的引导词who/whom/which/that/where/when/why+主语+谓语动词+...
I like music which/that I can dance to.
五、从句的时态
状语从句的时态受主句时态的影响，状语从句与主句的时态对应有四条时态原则：
一) 主句用现在时，状语从句用现在时
1. He often doesmorning exercises after he gets up.
2. Although she studieshard,she doesn’t do well in all her subjects.
二）主句用过去时，状语从句用过去时
1.I sawhim when I looked up just now.
2.We were walkingin the street when we met her yesterday evening.
3.We mether when(或while)we were walking in the street yesterday evening.
4.He was doinghomework when(或while)his brother was watching TV yesterday.
三）主句用一般将来时或祈使句或含情态动词，状语从句用一般现在时
这条时态原则（也就是平常所说的“主将从现”）考得最多，那么，要知道这条时态原则适用于什么情况，这条时态原则适用于时间状语从句（since所引导的除外）和条件状语从句。
1. Wewill go hiking if it doesn’t rain tomorrow.
2. Please cometo my home when you have time.
3. Youcan catch up with others as long as you study hard enough.
四）主句用现在完成时，since从句用一般过去时
He has workedin this company since he graduated from a university.
宾语从句的时态也受主句时态的影响，宾语从句与主句的时态对应有两条时态原则：
一）主句用现在时或将来时，宾语从句可根据实际情况用任何时态
1. Idon’t know where he lives.
2. The teacher wonderswhat they are doing.
3. I believehe will come to join us.
4. Iwant to know how many times you have been there.
5. Doyou know why they stayed up so late last night?
二）主句用过去时，宾语从句也要用过去时态的某种形式
1. He asked if you would go with us.
2. I knew they were playing games this time yesterday.
3. She said she had been to Beijing twice.
注意：如果宾语从句表示的是普遍真理，即使主句用了过去时，宾语从句照样要用一般现在时。如：
The teacher told us that the earth goes round the sun.
定语从句的时态不受主句时态的影响，根据定语从句动作所发生的时间进行确定,但有时要注意与主句动作的先后关系。
1. This is the school where we studied for three years.
2. He is the boy who is handsome.
3. He is the boy who ran fastest in the race.
4. They talked about the school which/that they will build next year.
5. They were talking about the place which/that they would visit the next day.
6. They were talking about the place which/that had attracted them so much.
六、从句中谓语的数
在从句中，从句谓语的数与从句主语相一致，这点大家都懂。问题是在宾语从句和定语从句中，因为引导词本身可以作从句的主语，而引导词本身是看不出是单数还是复数的，这就要引起注意。
1. I don’t know who teaches us physics.
2. I wonder who are going there.
3. Can you tell me what makes you so sad?
上面三句含有宾语从句，在宾语从句中，who/which作从句主语时，从句谓语有可能是单数，也有可能是复数，但what作从句主语时，从句谓语用单数。
4. This is the music (which/that)I aminterested in.
5. I love musicwhich/that is popular.
6. I love songswhich/that are popular.
上面三句含有定语从句，在定语从句中，当引导词在从句中作主语时，定语从句的谓语的数要与先行词一致。
上面我们从六个维度出发，区分了初中阶段所学的三种从句。只要大家在学习、使用这三种从句时，紧紧把握好这六个维度，灵活处理，定能真正学好这三大从句。