考研英语中情态动词的用法整理

动词的考查一直是考研英语词汇中一项重要内容，而其中，又以情态动词的用法更成为历次考试的高频考点。今天，北外网课（北京外国语大学网络课程）老师就归纳了整理了考研英语中情态动词的各类用法，供大家参考。

1.表示已经发生的情况  

(1)must have +过去分词，表示对已发生情况的肯定推测，译为“(昨天)一定……”

My pain must have been apparent the moment Iwalked into the room, for the first man I met asked sympathetically: “Are youfeeling all right?”

(2)cant/couldn’t have +过去分词，表示对已发生情况的否定推测，译为“(昨天)一定没……”

Mary couldn’t have received my letter;otherwise she would have replied before now.

(3)may/might have +

过去分词，表示对已发生的事情做不肯定、可能性很小的推测，或事实上根本没发生，

译为“也许……”

At Florida Power’s Crystal River plant, a potentiallyserious leakage of radioactive water may have been unknowingly caused by anelectrician.    

2.表示虚拟语气、

(1)needn’t have+过去分词，表示做了不必做的事，译为“其实没必要……”。

As it turned out to be a small house party,we needn’t have dressed up so formally.

(2)should /should not have +过去分词，表示应该做某事但实际上未做，或本不应该做但实际上做了, 译为“本(不)应该……”

I regret having left the work unfinished; Ishould have planned everything ahead carefully.

(3)ought to have+过去分词，表示动作按理该发生了，但实际上未发生，译为“该……”，与should的完成式含义类似。

The porter ought to have called thefire-brigade as soon as he saw the fire in the stock, which went up in smoke.

(4)could have+过去分词，表示过去本来可以做但却未做，译为“完全可以……”

What you said is right, but you could havephrased it more tactfully.  

(5)may/might have + 过去分词，表示过去可以做但实际未做，译为“(那样)也许会……”

It might have been better to include morepunchy statistics and photos of equipment in the introduction to further assistfirst-time office automation managers.

3.几个情态动词常考的句型

(1)may/might (just) as well“不妨，最好”，与hadbetter相近。如：

Since the flight was cancelled, you mightas well go by train.

(2)cannot/can’t…too… “越……越好，怎么也不过分”，句型变体cannot…over…

You cannot be too careful when you drive acar.  

The final chapter covers organizationalchange and development. This subject cannot be overemphasized.

(3)usedn’t或didn’t use to为used to (do)的否定式。  

(4)should 除了“应该”一层意思外，考研大纲还规定要掌握其“竟然”的意思

I didn’t expect that he should have behavedlike that.