2016年12月英语六级语法：情态动词

 　　对于六级考试来说，除了基本的词汇量之外，基础的语法也是不可或缺的哦！那么，我们一起来学习吧！

　　1、情态动词的完成式

　　1)must have done——表示对过去的事情较有把握的、肯定性的推测，常译为“一定，准是，肯定”，其否定形式是can’t/couldn’thave done，意为“决不可能，不太可能”。

　　e.g. Since the ditch¹ is full of water, it must have rained last night.

　　2)should/ought to have done——表示过去应该做的却没有做，常含有后悔、责备、埋怨的口吻，意为“本应该”，“应该就好了”;

　　e.g. With all the work finished, I should have gone to your birthday party last night.

　　3)shouldn’t/ought not to have done——表示过去不该做的事却给做了，也常含有责备、不满之意，意为“本不该”。

　　e.g. You shouldn’t have gone back to work yesterday without the doctor’s permission.

　　4)may/might have done——表示对过去的事情的推测，但不十分有把握，意为“可能，或许已经” e.g. A traffic accident happened yesterday and a driver may have been hurt.

　　5)could have done——表示过去有可能或有能力做某事，而实际未做、未能实现的事;有时也表示轻度批评，意为“本来可以，完全可以”。

　　e.g. The gas leakage² could have been avoided if the gas company took immediate³ measures after the warning call.

　　6)needn’t have done——表示过去做了某事，但没有做的必要，意为“其实没有必要”。

　　e.g. I needn’t have bought all that wine——only three people came.

　　2、可作情态动词用的短语

　　would rather, would sooner, would (just) as soon, had rather, had better, had sooner, cannot but, may/might as well

　　[例1]You all those calculations⁴! We have a computer to do that sort of thing.

　　A. needn’t have done                 B. must not have done

　　C. shouldn’t have done              D. can’t have done

　　[例2]I to him because he phoned me shortly afterwards.

　　A. ought to have written            B. must have written

　　C. couldn’t have written            D. needn’t have written

　　[例3]You those letters. Why didn’t you

　　A. should post                       B. must have posted

　　C. should have posted           D. ought to post

1 ditch   

n.沟，沟渠，渠道

参考例句：

• With the blind leading the blind, both shall fall into the ditch.如果瞎子替瞎子带路的话，那么两方肯定会掉到沟里。
• The water in the ditch is not very clean.沟里的水不很清洁。

2 leakage   

n.漏，泄漏；泄漏物；漏出量

参考例句：

• Large areas of land have been contaminated by the leakage from the nuclear reactor.大片地区都被核反应堆的泄漏物污染了。
• The continuing leakage is the result of the long crack in the pipe.这根管子上的那一条裂缝致使渗漏不断。

3 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

4 calculations   

n.计算( calculation的名词复数 )；盘算；自私的打算；推断

参考例句：

• We can exclude the possibility of total loss from our calculations. 我们可以在预测中把彻底失败的可能性排除在外。 来自《简明英汉词典》
• He scored out both calculations and did them again. 他把两个计算结果都划掉，又把它们计算了一遍。 来自《简明英汉词典》