名词性从句是什么
名词性从句是在句子中起名词作用的句子。名词性从句的功能相当于名词词组,它在复合句中能担任主语、宾语、表语、同位语、介词宾语等,因此根据它在句中不同的语法功能,名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
1、主语从句
What he wants to tell us is not clear. 他要跟我们说什么,还不清楚。
It's a great pity that they didn't get married. 他们没能结婚,真是令人惋惜。
2、宾语从句
He has told me that he will go to Shanghai tomorrow. 他已经告诉我他明天要去上海。
I insist that she (should) do her work alone. 我坚持要她自己工作。
3、表语从句
The fact is that we have lost the game. 事实是我们已经输了这场比赛。
It looks as if it is going to rain. 看上去天要下雨了。
4、同位语从句
The news that we won the game is exciting. 我们赢得这场比赛的消息令人激动。
I have no idea when he will come back home. 我不知道他什么时候回来。
注意:同位语从句和定语从句的区别
that作为关系代词,可以引导定语从句,充当句子成分,在从句中作宾语时可以省略; that引导同位语从句时,起连词的作用,没有实际意义,不充当句子成分,一般不能省略。
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