Question

情态动词+动词完成时 的问题

情态动词+动词完成时
老师说是表示对已发生的事情进行推测.
如The road is wet. It must have rained last night.

但Mike can't have found his car, for he came to work by bus this morning.
这句的时态不是从过去一直到现在都没找到吗？

希望指导下
我是想问‘情态动词+动词完成时’是否可以表示过去发生的事
即一般过去时

和表示从过去到一直现在，即现在完成时

这2个时态

Answer 1

1.must have + done 对过去的动作的肯定推测。

2.can't have found 对过去的动作的否定推测。
就是因为没有找到，才有此推测的啊。

Answer 2

can't have done sth. 表示不可能已经做了某事, 是一个习惯用法,Mike can't have found his car 说明不可能已经找到他的汽车.

Answer 3

can't 译为不可能
就是说麦克不可能找到他的车,因为他今天早上坐公交车来上班的

Answer 4

1.must have + done 对过去的动作的肯定推测。

2.can't have found 对过去的动作的否定推测。

情态动词是高考试卷上的必考语法点，其中以must，can/could，may/might表猜测时的用法最难以把握。在下文中，笔者尝试帮助你理清它们用法的区别。

1． must

表示推测时，must一般只用于肯定句。
（1） 对现在一般情况的猜测，常用“must + 动词原形”的结构，意为“一定”。
例1 You must be ill. I can see it from your face.你一定是病了，我从你的脸上看出来的。
例2 You must have the wrong number. There is no such person.你一定是弄错了号码，没有这样一个人。
（2） 对现在正在进行的行为的猜测，常用“must be + 动词的现在分词”的结构，意为“一定正在”。
例3 Something must be burning. I can smell it.一定是有什么在燃烧，我闻到了。
例4 George must be working in the office now. Look! The light is still on. George现在一定正在工作。看，灯还亮着。
（3） 对将来的猜测，可直接用“must be +动词的现在分词”的结构。
例5 They must be arriving early this morning.他们今天上午一定会早点到达的。
（4） 对过去或已发生的事情进行肯定的猜测时，常用“must have +动词的过去分词”的结构。
例6 The teacher have thought Johnson was worth it or she wouldn’t have wasted time on him, I suppose.
A. should B. can
C. would D. must
点评： 答案为D。句意为：“老师一定认为Johnson值得培养，否则她也不会在他身上花费时间了。”
例7 —She looks very happy. She have passed the exam.
—I guess so. It’s not difficult after all.
A. should B. could
C. must D. might
点评： 答案为C。前一句句意为：“她看起来很高兴，一定是通过了考试。”

2. can/could

（1） can常用于表示否定或疑问的猜测，表达不相信、疑惑、惊讶等意思。
①对现在一般情况表示疑问和否定的猜测，常用“can/can’t +动词原形”的结构。
例8 Mr. Bush is on time for everything. How it be that he was late for the opening ceremony?
A. can B. should
C. may D. must
点评： 答案为 A。句意为：“Bush先生做什么都很准时，他怎么会在开幕典礼上迟到呢？”
例9 You be tired—you’ve only been working for an hour.
A. must not B. won’t
C. can’t D. may not
点评： 答案为C。句意为：“你不可能会累的——你才工作了一个小时而已。”
②对过去情况表示疑问和否定的猜测，常用 “can/can’t have +动词的过去分词”的结构。
例10 My MP4 player isn’t in my bag. Where I have put it?
A. can B. must
C. should D. would
点评： 答案为A。句意为：“我的MP4播放器不在包里，我把它放在哪里了呢？”
例11 —Do you know where David is? I couldn’t find him anywhere。
—Well. He have gone far—his coat’s still here.
A. shouldn’t
B. mustn’t
C. can’t
D. wouldn’t
点评： 答案为C。前一句句意为：“你知道David在哪里吗？我到处都找不到他。”后一句句意为：“哦，他不可能走远——他的外套还在这里。”
（2） can有时也可用于肯定猜测，多表示客观存在的或理论上的可能性，常常用于说明人或事物的特征。
例12 The World Wide Web is sometimes jokingly called the World Wide Wait because it be very slow.
A. should B. must
C. will D. can
点评： 答案为D。句意为：“万维网有时被打趣地叫作长等网，因为网速有时会很慢。”其中，“网速有时会很慢”既是一种可能性，也是客观存在的情况。
（3） could的用法和can 相似，但语气比can弱。
①“could/couldn’t have ＋动词的过去分词”的结构可用来表示对过去或已发生情况的疑问和否定的猜测，语气比用can/can’t 时弱些。
例13 —There were already five people in the car but they managed to take us as well.
—It a comfortable journey.
A. can’t be
B. shouldn’t be
C. mustn’t have been
D. couldn’t have been
点评： 答案为D。前句句意为：“车里已经有五个人了，但他们还要再加上我们。”后句意为：“这不可能是一次舒适的旅行了。”
②除可用于表示否定和疑问的猜测外，could还可用于肯定句，表示可能性，此时相当于may的含义。
例14 —I’ve taken someone else’s green sweater by mistake.
—It Harry’s. He always wears green.
A. has to be B. will be
C. mustn’t be D. could be
点评： 答案为D。前句意为：“我穿错了别人的绿色毛衣。”后句意为：“可能是Harry的，他一直穿绿色。”

3. may/might

表示猜测时，must语气最强，can / could语气稍弱，may / might最弱。may/might可以对现在、过去或将来的情况进行肯定或否定的猜测，might可视为 may的过去式，语气比may更弱。
（1） “may / might +动词原形”表示对现在或未来的可能性的判断。
例15 —Is John coming by train?
—He should, but he may not. He likes driving his car.
—John是坐火车来吗？
—应该是的，但也可能不。他喜欢自己驾车。
（2） 对正在发生的事进行推测，常用“may/might be +动词的现在分词”的结构.
例16 Let’s speed up. They may/might be waiting for us now.让我们加快速度，他们可能正在等我们。
（3） 对发生在过去的情况进行猜测，可用“may/might have +动词的过去分词”的结构。
例17 —Where is my dictionary? I remember I put it here yesterday.
—You it in the wrong place.
A. must put
B. should have put
C. might put
D. might have put
点评： 答案为D。前句句意为：“我的字典在哪里？我记得昨天把它放在这儿的。”后句意为：“你可能放错地方了。”

【练习题】

1．—Why! I didn’t get you on the phone.
—We basketball on the playground when you phoned.
A. must be playing
B. can have been playing
C. might have played
D. must have been playing

2. You Bob at the meeting yesterday; he has been on holiday in Paris for a week.
A. mustn’t have seen
B. shouldn’t see
C. can’t have seen
D. couldn’t see

3. —Are you going to the lecture tomorrow afternoon?
—I’m not sure now. I go to Prof. Black’s class instead.
A. might B. would
C. should D. must

4. I didn’t hear the bell ring. I asleep.
A. must be
B. must have been
C. should be
D. should have been

5. —I heard they went skiing in the mountains last winter.
—It true, because there was little snow there.
A. may not be
B. won’t be
C. couldn’t be
D. mustn’t be

6. —Isn’t that Ann’s husband over there?
—No, it be him. I’m sure he doesn’t wear glasses.
A. can’t B. must not
C. won’t D. may not

7. —Look， John’s fallen asleep.
—Oh， he too late last night.
A. might stayed up
B. should have stayed up
C. could stayed up
D. must have stayed up

Answer 5

情态动词+动词完成时，是表示对已发生的事情进行推测.
如The road is wet. It must have rained last night.

但Mike can't have found his car, for he came to work by bus this morning.
这句的时态不是从过去一直到现在都没找到吗。
你说得对。 情态动词是must ，不是其它的情态动词。
我是从事英语的，不明再问啦。

Answer 6

find是非延续性动词,意思是找到，所以只表示过去没有找到这一结果，而非从过去一直到现在都没找到