13.2 it作形式主语 

 

当句子的主语是不定式、动名词或主语从句时,常常可以用it作形式主语,而把真正的主语移到句子后部。用it作形式主语的好处是避免句子由于主语太长而显得头重脚轻。 

 

13.2.1 it作不定式的形式主语 
 

1) it + be + 形容词 + 不定式 
It is difficult to get there before dark. 天黑以前赶到那里很困难 
It is better to get up early. 早起会更好 

 

2) it + be + 名词 + 不定式 
It was his duty to attend to this matter. 处理这个问题是他的责任 
It is the file system's job to manage writing data between the disks and memory.  

在内存和磁盘上管理数据是文件系统要处理的东西。 

 

3) it + 动词 + 宾语 + 不定式 
It takes a lot of effort to recover the system. 恢复系统不是一件容易的事情 
It makes me sad to hear that you have to go away. 听说你一定要走,我很难过 

 

4) it + be + 介词短语 + 不定式 
It is against the law to steal. 偷窃是犯法的 

 

13.2.2 it作动名词的形式主语 
 

1) it + be + 名词 + 动名词 (常用的名词有no good, no use, nuisance, a waste, a wonder 等) 
It’s a wonder meeting you here! 在这里遇见你真是个奇迹 
It’s no use doing a lot of work without thoughtful planning.  

没有考虑周到的计划而做一大堆工作是没用的。 
 

2) it + be + 形容词 + 动名词 
It was very difficult getting everything ready in time. 要及时做好一切准备很难 
Is it worthwhile hating each other over such a trifle? 为了这么点事儿,你俩至于结冤吗 

 

3) 其他情况 
It doesn’t matter putting these two files together. 把这两份文件放在一起没关系 
It doesn’t make any difference my being here. 我是否在这儿并不能改变什么 

(注:这里my为动名词的逻辑主语 

 

13.2.3 it作主语从句的形式主语 
 

1) it + be + 形容词 + 从句 
It is clear that the chosen pattern is not the correct one. 显然,所选择的图式是错误的 
It is doubtful whether this method is more scientific. 这个方法是否更科学值得怀疑 

 

2) it + be + 名词 + 从句 
It is a pity that we shall have to leave tomorrow. 我们明天必须离开,真是遗憾 
It is a complete mystery what caused the accident. 是什么引起这场事故完全是个谜 

 

3) it + 动词 (+宾语或状语) + 从句 
It matters little who does it so long as it is done. 只要事情做了,谁做都行 
It happens that his sister is a closed friend of mine. 碰巧她姐姐是我的一个好朋友。  

 

4) it + 动词的被动语态 + 从句 
It is said that the rhythm of tides is affected by the moon. 据说潮汐的涨落受月亮的影响 
It is estimated that the output will increase by 20% this year. 今年预计产量将提高20%。 

 

5) it + 介词 + 从句 
It is out of question that China's economy will keep growing for 40 years.  

中国经济增长40年应该不成问题。