名词性从句三大用你知道吗？记住一个that,一个whether, 轻松搞定

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名词性从句三大用你知道吗？记住一个that,一个whether, 轻松搞定

名词性从句中，该怎么区分that 和whether

名词性从句的用法

名词性从句中,该怎么区分that 和whether

一、名词性从句三大用你知道吗？记住一个that,一个whether, 轻松搞定

名词性从句

名词性从句就是由陈述句或问名变成名词的从句，听起来是不是好难理解，关键它还有两种，一种是陈述句变成的，一种是问句变成的。以句见真章，我们来看看。

陈述句变形名词性从句

我们先来看个例子：

陈述句：

Marco doesn't watch TV.

马克不看电视。

--变成名词性从句，在句首加that

that Marco doesn't do exercise.

马克不做运动。

再来看一个句子：

Love is the best teacher.

热爱是最好的老师。

--变成名词性从句，在句首加that

that love is the best teacher.

热爱是最好的老师。

从上面两个句子都可以看出，名词性从句之前都是连词that引领，此时，该名词性从句可被看作一个整体名词，在句中作主语，宾语，或置于be动词之后作为补足语。

这样做有什么用处呢？我们来看下例子：

作主语用

That Marco doesn't do exercise makes him fatter.

马克不做运动 让 他变得更胖了。

作宾语用

I believe that love is the best teacher.

我 相信 热爱是最好的老师。

be动词之后作补足语

My firm is that love is the best teacher.

我的信念 是 热爱是最好的老师。

一般疑问句变成名词性从句

还记得我们在解析一般疑问句的时候就说过，一般疑问句就是可以用YES/ NO 来回答的问句，一共有三种情况：

以be动词为首引领的一般疑问句

Is Marco a good teacher?

马克是一个好老师吗？

Are they having meeting now?

他们正在开会吗？

--变成名词性从句，句首以连词whether(是否）引领，主语次之，be动词第三，即

Whether Marco is a good teacher

马克是不是好学生

Whether they are having meeting now

他们现在是否正在开会

以助动词do/ does/ did 为首引领的一般疑问句

Do you want some coffee?

你想要来一些咖啡吗？

Does Lily finish the homework?

丽丽完成作业了吗？

Did you see the new moive yesterday?

你昨天看了那部新电影吗？

--变成名词性从句，句首一样以连词whether（是否）引领，不再使用助动词do/does/did，之后的动词还原成对应人称应使用的形态，有点难理解，以例子为证：

Do you want some coffee?--变形三步骤

句首以whether引领去掉助动词do动词为want，前面的you是第二人称单数，动词不变，为want

完整句子就是： Whether you want some coffee

你是否想要来一些咖啡吗

Does Lily finish the homework?--变形三步骤

句首以whether引领去掉助动词does动词为finish， 前面的lily是第三人称单数，动词变形为finishes

完整句子就是：Whether lily finishes the homework

丽丽是否完成作业了

Did you see the new movie yesterday?--变形三步骤

句首以whether引领去掉动词did动词为see，前面的you 是第二人称单数，动词不变，但时态为过去时态，动词应变为saw.

完整句子就是：Whether you saw the new movie yesterday.

你昨天是否看了那部新电影

由情态动词(can、may、will、should、could、would等)为首引领的一般疑问句

Can you help me?

你可以帮我吗？

Will Peter join the team building tomorrow?

彼得明天会来参加团建活动吗？

--变成名词性从句，句首还是一样以连词whether（是否）引领，助动词置回主语之后,即

Whether you can help me.

你是否能帮我

Whether Peter will join the team building tomorrow

彼得明天是否会来参加团建活动

一般疑问句变名词性从句，跟陈述句变名词性从句一样，该名词性从句可被看作一个整体名词，在句中作主语，宾语，或置于be动词之后作为补足语。

作主语

Whether Marco is a good teacher remains to be seen.

马克是不是一个好老师 有待观察。

作宾语

I wonder whether lily finishes the homework.

我 好奇 丽丽完成了作业没有。

3.置于be动词之后作补足语

My question is whether Peter will join the team building tomorrow.

我的问题 是 彼得明天是否会来参加团建。

一、名词性从句中，该怎么区分that 和whether

1. 关于if与whether：两者都可引导宾语从句，常可换用; 但若引导主语从句，则用whether (不用if)。　　
2. 关于whether和that：两者都可引导主语从句，其区别主要应从句意来考虑：whether表示“是否”，由它引导的主语从句的意思通常是不确定的；that 引导主语从句时，本身没有词义(that在其他名词性从句中也没有词义)，但是由that引导的整个主语从句的意思通常是确定的。

二、名词性从句的用法

名词性从句就是句子担任名词性的成分，如主语，宾语，表语，同位语。它包括主语从句、宾语从句、表语从句和同位语从句。
1. 主语从句
（1）What he said is true.
（2）When they will arrive is not known yet.
（3）That he succeeded in doing the experiment was encouraging.
（4）Whether he will accept the invitation remains a secret.
（5）It is important that we should learn English well.
2. 宾语从句
（1）I don't know if he has done the work.
（2）Did he say that he liked football ?
（3）They expected that they would be given another chance.
（4）The girl told me that she had longed to visit China.
3. 表语从句
（1）The question is whether we have enough time to do the experiment again.
（2）His greatest wish was that someday he would become a general.
（3）His suggestion was that we should discuss the plan carefully.
（4）My question is when they can finish the work.
4. 同位语从句
（1）You have no idea how eager they are to know the result.
（2）He made a suggestion that the work should be given to him.
（3）Have you heard the news that Premire Wen visited our school last Friday ？
（4）The fact that he got full mark in the composition made his parents very happy.

名词性从句主要从以下几点把握：
1. 语序。从句一定要是陈述语序。如：
（1）These pictures will show you what the village looks like now.
（2）How many guests will be invited isn’t decided yet.
2. 时态。宾语从句的时态需要和主句进行协调。如主句是过去时，从句要用相应的过去时。
（1）He told me that he had seen the film.
（2）They said they would spend their holiday in Hainan.
（3）Father said he was carrying out an important project.
（4）Did you know where the accident took place ?
3. 连词。引导名词性从句的连词分为三种：连词 that, whether, if （在主语、表语、同位语从句中用 whether 不用if ）；连接代词 who, whom, whose, which, what 等; 连接副词 when, where, how, why 等。
（1）Whether the team has won the game is not announced yet. （主语从句）
（2）How many people will take part in the competition will be known soon. （主语从句）
（3）My idea is that we should spend our holidays by the seaside. （表语从句）
（4）My question is how they finished the work in such a short time. （表语从句）
（5）Many people are shocked at the news that there are so many SARS cases in Beijing. （同位语从句）
（6）His suggestion that we should discuss the plan again has been received. （同位语从句）
（7）I didn’t know if they had seen the film. （宾语从句）
（8）We haven’t decided when we’ll start the project. （宾语从句）
4. 形式主语和形式宾语的应用：
当主语从句比较长，主句比较短时，通常用形式主语it，而把从句放在后面，如：
（1）It is said that they have succeeded in working out the problem.
（2）It was important that we should make the plan carefully.
（3）It remains a secret how the animals came to live in the sea.
当宾语从句后面有补语的时候,我们也需要用形式宾语it, 而将宾语从句放在补语之后,如：
（1）I found it very difficult that one learns several languages at the same time.
（2）He thinks it necessary that we should be given more time practising oral English.
（3）He made it clear that he would leave the office soon.
5. 虚拟语气在名词性从句中的运用: 在demand， insist， suggest， command， require， request， order， propose 等表示命令， 要求，请求，建议等意义的动词后，宾语从句要用虚拟语气，动词形式为: should do ， should 可省，直接用动词原形，如:
（1）He suggested that we （should） go outing this weekend.
（2）The Emperor ordered that the clothes （should） be made for him at once.
（3）He insisted that we （should） stay for lunch.
这种虚拟语气也可以运用在其他的名词性从句中,从句内容不变, 如:
（1）It was suggested that we should go outing this weekend. （主语从句）
（2）He made a suggestion that we should go outing this weekend. （同位语从句）
（3）His suggestion was that we should go outing this weekend. （表语从句）
6. 定语从句与同位语从句的区别:
定语从句修饰前面的名词,而同位语从句说明前面名词的内容,引导定语从句的that在从句中担任名词性成分,而同位语从句中的 that 不担任任何句子成分.如:
（1）Have you heard the news that was broadcast this morning ? （定语从句）
（2）Have you heard the news that we defeated the Japanese football team ?（同位语从句）
（3）What do you think of the suggestion that was put forward by Lily ?（定语从句）
（4）What do you think of the suggestion that we should speak only English in class ?（同位语从句）
7. 几个容易混淆的连词：
A. whether 和 if：whether可以用在所有的名词性从句中；而if 只能用于宾语从句，另外，如果有介词的话，仍然用whether。
（1）Whether the advice will be accepted is not known. （主语从句,不可以用if）
（2）I have no idea whether he will come. （同位语从句,不可以用if.）
（3）The problem is whether we have enough time to do it again. （表语从句,不可以用if .）
（4）He didn’t tell me whether （if ） he would accept my invitation. （宾语从句,两者都可以）
（5）Everything depends on whether we have enough manpower. （介词之后不用if ）
B. what 和 that：that 在名词性从句中不担任句子成分；what 在名词性从句中做主语，宾语，表语等，通常译为”所．．．的”，如：
（1）What we have done is very important. （what 做宾语）
（2）That they have done the work is good news. （that 无句子成分）
（3）I believe what he said. （what 做宾语）
（4）I believe that he told truth. （that 无句子成分）

三、名词性从句中,该怎么区分that 和whether

1.从作用判断：that 只起连接主句和从句的作用,没有具体的意思；whether在句子里担当成分,有是否的意思2.从句子类型判断：if与whether：两者都可引导宾语从句,常可换用; 但若引导主语从句,则只用whether 3.从句意判...