名词性从句的用法
在句中起名词作用的从句称为名词性从句。名词性从句可以作主语、宾语、表语和同位语,用法如下:
1.主语从句
主语从句是在复合句中作主语的名词性从句,通常放在主句谓语动词之前。
1)由that引导的主语从句
①引导词that无意义,在句子不作任何成分,同时不可以省。that引导的主语从句通常用it作形式主语。
That he doesn’t tell a lie is true.
(=It is true that he doesn’t tell a lie.)
他没有说谎,是真的。
②由that引导的主语从句用形式主语it开头,而从句本身放在句末,常见的有四种句型。
It is+名词+that从句。如:
It is a fact that... 事实是......
It is a pity that... 可惜的是......
It is+形容词+that从句。如:
It is (un)likely that... 很有(不大)可能......
It is strange that... 奇怪的是......
It is+过去分词+that从句。如:
It is said that... 据说......
It is reported that... 据报道......
It is+不及物动词+that从句。如:
It seems that... 似乎......
It happened that... 碰巧......
2)由连接代词what, who, whom, whose, whoever, whomever, whichever, whatever等引导的主语从句
连接代词在句中起名词性作用,担任一定的成分。
What you need is more practice.
你需要的是dafabet888的练习。
Whoever wants to come is welcome.
无论谁来都欢迎。
3)由连接副词when, where, why, how等引导的主语从句
连接副词有意义,在句中作状语。
When he will come has not been clear.
(=It has not been clear when he will come.)
他何时来还不清楚。
How he solved the problem still puzzles me.
他怎样解决这个问题的至今仍令我费解。
4)由whether与if引导的主语从句
whether通常用于正式的语体中,if多用于口语中。此外,if引导的主语从句只能放在句后,还不能与or not连用。
Whether she comes or not doesn’t matter too much.
她来不来都没有关系。
It is unclear whether/if he likes the present.
他是不是喜欢那个礼物还不清楚。
2.宾语从句
宾语从句是在复合句中作宾语的名词性从句,通常放在主句谓语动词(及物动词)或介词之后。
1)作动词的宾语
①由that引导的宾语从句(that通常可以省)
I think (that) he is a good actor.
我认为他是位好演员。
I heard it that you have got the first prize in the examination.
我听说你在考试中取得了第一名。
②由连接代词what, which, who, whom, whose, whoever, whomever, whichever, whatever等引导的宾语从句
I don’t know who is coming to the party.
我不知道谁会来参加聚会。
③由连接副词when, where, why, how等引导的宾语从句
I will tell you why I was late for the meeting.
我会告诉你我为什么开会迟到了。
④动词+间接宾语+宾语从句
She told the teacher that she would study hard.
她告诉老师她会努力学习。
⑤由whether与if引导的宾语从句
whether和if引导的宾语从句可以互换使用,但介词后的宾语从句和不定式前只能用whether, 不能用if。此外,whether后可以加or not, if 不可以。
I wonder whether you can help me.
我想知道你能否帮我忙。
2)作介词短语的宾语从句
Our success depends upon what we do and how we do it.
我们的成功取决于做什么和怎么做。
3)作形容词的宾语从句
I am afraid (that) I’ve lost my way.
恐怕我迷路了。
3.表语从句
表语从句是在复合句中作表语的名词性从句,通常放在系动词之后。
1)由从属连词that, whether, as if, as though, as, because等引导的表语从句
The fact is that he didn’t attend the meeting.
事实是他并没有出席会议。
It looks as if we will be late.
看起来我们似乎会迟到。
2)由连接代词what, who, whom, whose, whoever, whomever, whichever, whatever等引导的表语从句
He is no longer what he used to be.
他不再是过去的他了。
3)由连接副词when, where, why, how等引导的表语从句
This is where the great man once lived.
这是这个伟人曾经居住过的地方。
4.同位语从句
同位语从句是在复合句中作名词的同位语的名词性从句。
1)由从属连词that或whether引导的同位语从句
We heard the news that our team had won.
我们听到消息说我们队赢了。
Please answer my question whether you will accept the job.
请回答我的问题,你是否接受这份工作。
2)由连接代词引导的同位语从句
I have no idea what you meant.
我不明白你是什么意思。
3)由连接副词引导的同位语从句
I have no idea when he will come back.
我不知道他什么时候回来。