2024年3月3日发(作者：)
语法讲座之九：名词性从句和定语从句和状语从句
一、名词性从句
名词性从句指主语从句、宾语从句、表语从句和同位语从句。
（一）主语从句
1．主语从句的引导词：wh- / that 。例如：
That he will accept the offer seems unlikely.
That he always studies hard is known to us.
What they are after is profit.
Who will go with you hasn’t been decided yet.
2. 如果主语太长或为了保持句子的平行，绝大部分主语从句用it作形式主语，将真正的主语从句放在后面。例如：
① It is + 形容词+that
② It is + 名词+that
③ It is + 动词+that
It is likely that it is going to rain. ①
It is no use that you go there in person. ②
It is known that football is played all over the world. ③
(二) 宾语从句
宾语从句的引导词：wh- / that 。例如：
We must find out who did all this.
He told me (that) he could do it for me.
He has made it clear that the meeting will not be postponed.
注意：if 和whether在引导宾语从句时的特殊用法
① whether or not / whether…or not 连用是固定搭配，这时，whether 不能用if来替换。
② 如果宾语从句是否定句时，只能用if而不能用whether来引导。例如：
I don’t care if it doesn’t rain.
I don’t care if the factory doesn’t have my pay raised.
(三) 表语从句
表语从句的引导词：wh- / that 。表语从句出现在系动词之后。
（四）同位语从句
1．同位语从句与定语从句的区别：
同位语从句与先行词之间是等同关系，而定语从句与先行词之间是修饰语被修饰关系。
2．同位语从句的标志词：
News, opinion, fact, belief, thought, idea, feeling, conclusion, suggestion, order, evidence,
decision等。
3．同位语从句的引导词：that, whether, where, when, what, how, why.
同位语从句的引导词that没有实际意义，只起到连接作用，that 不能用which所代替。
例如：
The idea that one can do the job without thinking is wrong.
There is no doubt whether the experiment will take place as scheduled.
There can’t be any doubt that the experiment will take place as scheduled.
You have no idea how excited I was.
Nobody can explain the mystery why she suddenly disappeared.
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4. 同位语从句有时不是紧紧跟在先行词之后的，这是为了句子平行的需要。值得注意的是这时的同位语从句很不易被发现，同学往往不能分辨出被其他句子成份所割裂了的同位语从句。例如：
The problem then arose what contribution the public should pay.
The thought came to her that she had an appointment with the dentist that afternoon.
The news came that our team won the game.
二、定语从句
1． 定义：定语从句又叫形容词性从句，在句子中起修饰、限定作用。
2． 引导词：关系代词---that, who, which, whose, whom和
关系副词---when, where, why
3. 限定性和非限定性定语从句：
形式上，限定性定语从句不需用“，”号隔开，而非限定性从句需要用“，”号隔开。
意义上，限定性定语从句与先行词关系紧密，一般不能省略；而非限定性定语从句与先行词之间的关系不是很紧密，省略了也不会影响整个句子的意义。试比较：
They have two children who were still at school. （强调“还在上学”）
They have two children, who were still at school. （强调“只有两个孩子”）
4．关系代词和关系副词的选择：
表一：关系代词
功能
作用
主语
宾语
定语
限定性和非限定性定语从句
代替人
who
whom
Whose=of whom
which
which
Whose=of which
代替物
that
that
仅限于限定性定语从句
代替人或物
表二：关系副词
用法
关系副词
When=at /in /during which
Where=in / at which
Why=for which
5.必须用that引导的定语从句
1）当先行词含有最高级的时候
2）当先行词含有the only的时候
3）当先行词中既有人又有物时
4）当先行词为不定代词时
5）当先行词含有序数词时
eg.
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被替代的先行词
表示时间的名词
表示地点的名词
reason
在从句中的作用
时间状语
地点状语
原因状语
He is the best singer that I have ever known.
The only great scientist that lived a simple life is Einstein.
These are the students and the stories that I told you.
Is there anything that I can do for you?
The Sound of Music is the first English film that I have ever seen.
6．As 引导的定语从句：
定语从句中如果出现expect, know, show, point out, imagine等词，关系代词一般用as。常见
的结构有：
As is known to all, as is often the case, as is natural, as has been said before, as is shown in the
figure
三、状语从句
状语从句的分类：时间、地点、原因、目的、结果、让步、条件、方式、比较共9种。
注意事项：表示让步，英语中不可以说though/although…but, 但可以说：
Although / though / while / even if … yet / still / however / nevertheless
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