语法基础3第三节——主语从句
一、 什么是主语从句
【试译】女人总是对的是一个常识。
That ladies tend to be right is common knowledge.
修改一下：It is common knowledge that ladies tend to be right.
小结：
主语从句放到句末，用It 来做形式主语。
二、主语从句的考点分析
主语从句在写作中的满分表达就是使用 it 作形式主语
① It has been widely accepted that... 人们普遍认为 / 众所周知......
② It is self-evident that... ......是显而易见的。
③ It is common knowledge that... ......是一个常识。
④ It is generally agreed that... 人们普遍认为 / 众所周知......
⑤ It is my belief that... = I think that... 我认为......
⑥ It is universally acknowledged that... 人们普遍认为 / 众所周知......
⑦ It has been found that... 人们已经发现......
⑧ It is beyond dispute that... ......是毋庸置疑的。
本句型可以写在作文中任何一句话的前面，用来拉长句子。
举例：
① It is common knowledge that a positive attitude plays a key role in achieving success.
【翻译】积极的心态对于成功至关重要，这是一个常识。
② It is my belief that the issue about pollution should be brought into the limelight under modern conditions.
【翻译】我认为关于污染这个话题现在应该引起人们的关注。
三、如何识别主语从句？
只要见到有引导词放在句首，只有两种可能性：一是主语从句，二是状语从句。如何排除状语从句？答：状语从句后面一般有个逗号。
只要见到引导词放在句首，中间没有用逗号隔开，就一定是主语从句。主语从句从句首开始，到主句的谓语动词之前结束。
除此以外见到 it...that 也是主语从句，主语从句到句末结束。it是形式主语。
练习：
① That he finished his homework in such a short time surprised us all.
他在如此短的时间内写完作业使我们十分惊讶。
②For example, it has long been known that total sleep deprivation is 100 percent fatal to rats, yet, upon examination of the dead bodies, the animals look completely normal.
比如说，长期以来众所周知，完全剥夺睡眠对老鼠来说是绝对致命的， 但是通过检查尸体，这些动物看起来又完全正常。
③ For the low-sympathy kids, how much they shared appeared to turn on（取决于）how inclined they were to feel guilty.
对于同情心不足的孩子来说，他们愿意分享多少似乎取决于他们内疚的程度。
④ It is generally agreed that a person of high intelligence is one who can grasp ideas readily, make distinctions, reason logically, and make use of verbal and mathematical symbols in solving problems.
普遍认为，一个高智商的人是一个这样的人：他能够轻易地理解他人的想法，能够做出辨别，能够进行逻辑推理，并且还能使用文字和数学符号来解决问题。
⑤ How well the predictions will be validated by later performance depends upon the amount, reliability, and appropriateness of the information used .
以后的行为多大程度上能够证明这些预言取决于所使用的信息的数量、可靠性和适合性。
⑥ Whether the Government should increase the financing of pure science at the expense of technology or vice versa often depends on the issue of which is seen as the driving force.
政府应该以牺牲技术为代价增加对纯科学的投入，还是以牺牲纯科学为代价增加对技术的投入，这取决于哪一个被视为驱动力的问题。
小结：
首先，引导词出现在句首，且和主句的谓语动词（词组）之间没有逗号，那么句首的从句就一定是主语从句。主语从句从句首开始到主句的谓语动词（词组）之前结束。
其次，很多句子中，也会出现主语从句后置的情况，所以见到 it... that（强调句除外）通常也是主语从句，主语从句从 that 开始到句末结束。
