情态动词表推测的常考考点

（摘自《第二课堂》）

一、考查百分之百可能性的推测

英语中表示百分之百的可能性，用情态动词must，意思是“一定”“肯定”，所作出的推测几乎接近事实。如：

Now sit down and make yourself comfortable. You must be very tired. 现在坐下来，让自己舒服些，你一定很累了。

若是要对过去情况作肯定推测，则要用“must+完成式”。如：

He must have come this way; here are his footprints. 他一定是走这条路来的，这里还有他的脚印呢。

His only explanation was that he must have brought them home in order to continue his work. 他唯一的解释是，自己想必是为了继续工作而把它们带回家了。

【真题验证】（答案分别为DB）

1. Harry is feeling uncomfortable. He ______ too much at the party last night. (2013辽宁卷)

A. could drink           B. should drink          C. would have drunk  D. must have drunk

2. Since nobody gave him any help, he ______ have done the research on his own. (2013课标卷II)

A. can                      B. must                     C. would                   D. need

二、考查具有较大的可能性的推测

表示可能性较大的情态动词主要有may, should, ought to，它们大致相当于汉语的“可能”“应该”“按理会”。如：

You could try the drugstore, but it may well be closed by now. 你可以到杂货店去试试，但现在很可能关门了。

I wonder what’s happened to Annie. She should be here by now. 不知安妮出什么事了，到现在她应该到了。

若是要对过去情况作较大可能性的推测，则要用“may (should, ought to)+完成式”。如：

I should have gone this morning but I was feeling a bit ill. 今天早晨我本应该走的，但是我觉得有点不舒服。

【真题验证】（该知识点近两年高考考得比较少，主要以干扰项形式出现；答案均为B）

1. When I was a child, I ______ watch TV whenever I wanted to. (2013江西卷)

A. should                  B. could                    C. must                     D. need

2. It ______ be the vocabulary that caused you the problem in the exercise because you know a lot of words. (2013安徽卷)

A. may                     B. couldn’t                C. should                  D. needn’t

三、考查具有较小可能性的推测

在所有表示推测的情态动词中，might和could所表示的可能性最小，由于它们的语气较委婉，较不确定，所以往往相当于汉语的“可能”“也许”“说不定”等。如：

I might come and visit you in America next year, if I can save enough money. 如果我能存在足够的钱，我明年可能来美国探望你。

My wife's in hospital—our baby could arrive at any time. 我妻子住进了医院——我们的小宝宝随时都可能出生。

若是要对过去情况作较大可能性的推测，则要用“might (could)+完成式”。如：

He drove so fast; he might have had a bad accident. 驾驶那么快，他可能会出车祸的。

【真题验证】（答案分别为ADD）

1. —You needn’t take an umbrella. It isn’t going to rain.

—Well, I don’t know. It ______ do. (2013北京卷)

A. might                   B. need                     C. would                   D. should

2. —What are you doing this Saturday?

—I’m not sure, but I ______ go to the Rolling Stones concert. (2013重庆卷)

A. must                    B. would                   C. should                  D. might

3. I ______ myself more —it was a perfect day. (2013浙江卷)

A. shouldn’t have enjoyed                          B. needn’t have enjoyed  

C. wouldn’t have enjoyed                           D. couldn’t have enjoyed

四、考查理论上的可能性

表示理论上的可能性（即理论上有可能但实际上未必会发生的情况），英语通常是用can，且可以用于肯定句中。如：

Even an experienced climber can get into trouble. 哪怕是有经验的登山者也可能陷入困境。

Noise can be quite a problem when you’re living in a flat. 住在公寓里，噪音可能是一个不小的问题。

若不是表示理论上的可能性，则can只用于否定句或疑问句，而不用于肯定句。如：

If winter comes, can spring be far behind? 冬天来了，春天还会远吗?

You’ll see the building on your left. You can’t miss it. 那栋建筑在你的左手边。你一定不会看不到的。

同样地，若要对过去情况作推测，则要用“can+完成式”。如：

From her knowledge of Douglas’s habits, she feels sure that the attacker can’t have been Douglas. 根据她对道格拉斯生活习惯的了解，她敢肯定袭击者不可能是道格拉斯。

【真题验证】（答案分别为BA）

1. I______ thank you too much for all your help to my son while we were away from home. (2012陕西卷)

A. won’t                  B. can’t                 C. can                 D. will 

2. —Why are your eyes so red? You ______ have slept well last night.

—Yeah, I stayed up late writing a report. (2013四川卷)

A. can’t                    B. mustn’t                 C. needn’t                 D. won’t