在復(fù)合句中起名詞作用的從句叫名詞性從句,包括作主語(yǔ)從句、表語(yǔ)從句、賓語(yǔ)從句和同位語(yǔ)從句。
(1)主語(yǔ)從句
就是在復(fù)合句中作主語(yǔ)的從句。主語(yǔ)從句常用that, whether, who, whom, whose, what, which, when, where, how, why, whatever, whoever等引導(dǎo)。如:
Whether he will be able to come remains a question. 他是否來(lái)還是問(wèn)題。
That China is a great socialist country is well known. 眾所周知,中國(guó)是一個(gè)偉大的社會(huì)主義國(guó)家。
注:為避免頭重腳輕,使句子平衡,常用it作形式主語(yǔ),而將主語(yǔ)從句后置。如上述第二例常說(shuō)成:
It is well known that China is a great socialist country.
但是,由連接代詞what, whatever, whoever等引導(dǎo)的主語(yǔ)從句一般不能用形式主語(yǔ)。如:
What he found surprised me greatly. 他的發(fā)現(xiàn)使我非常吃驚。
Whoever is finished may rest. 凡是做完工的人都可以休息。
(2)表語(yǔ)從句
就是在連系動(dòng)詞之后作表語(yǔ)的從句。引導(dǎo)表語(yǔ)從句的連接除與引導(dǎo)主語(yǔ)從句的連接詞外,還有as if, as though。如:
The question is whether he is able to do it alone. 問(wèn)題是他能否單獨(dú)做這件事。
It looks as if (though) it is going to snow. 天好像要下雪似的。
注意:要區(qū)分以下句式:
1. that’s why+結(jié)果;that’s because+原因。2. the reason why /for…is that…
He is absent. That’s because he is ill. 他缺席,這是因?yàn)樗×恕?/p>
He is ill. That’s why he is absent. 他病了,這就是他缺席的原因。
The reason why he is absent is that he is ill. 他缺席的原因是他生病了。