Talking about possibility

and improbability

a. Many people think the monster may be related to Nessie.

b. They think there might be similar creatures in other lakes.

c. Scientists say the lake is unlikely to be able to support such a big creature.

Look at the sentences and answer the questions.

1. Which sentences say that something

is possible?

a, b

2. Which sentences say that something

is impossible?

c

3. Which word is followed by to + verb?

unlikely

may: 可能会 , 或许会might: 可能 , 或许 ( 语气更不肯定 )

unlikely: 可能性不大的 ( 形容词 )e.g. 1. It may be a new species.

它可能是一种新的物种。

他或许不在那儿。2. He may not be there.

3. His suggestion might be worth thinking

about.

他的建议或许值得考虑。

我有许多或许你感兴趣的书。

4. I have got a lot of books that might

interest you.

7 点钟前她可能到不了。

他不大可能受伤。

5. She is unlikely to arrive before 7.

6. It is unlikely that he got injured.

Rewrite the sentences using the

word in brackets.

1. Perhaps there are still dinosaurs

somewhere. (might)

There might still be dinosaurs

somewhere.

2. Don’t go near the water. Perhaps

it’s very deep. (may)

Don’t go near the water. It may be

very deep.

3. We probably won’t see the

monster. (unlikely)

We are unlikely to see the monster.

4. Perhaps there is an underground

river from Loch Ness to the sea.

There may be an underground

river from Loch Ness to the sea.

5. We must help him --- perhaps he

can’t swim! (may)

We must help him --- he may not

be able to swim.

6. There are probably lots of strange

creatures in that lake. (likely)

There are likely to be lots of

strange creatures in that lake.

may have / might have

a. The dinosaurs may have stopped

evolving, and been unable to adapt

to changes in the climate.

b. They might have killed each other.

Read the sentences from the

interview.

We use may have or might have (with

the past participle) to talk about ____.

1. Something which happened in the

past---perhaps.

2. Something which is impossible.

3. Something which may happen in the

future.

1

“may + have + done” 表示对发生过的事情的推测，意思是“可能已经”或“ 也许已经”，用于肯定句中。如 :

—What has happened to George?

—I don’t know. He may have got lost.

— 乔治发生了什么事？ — 我不知道，他可能迷路了。

“might+have+done” 表示对过去事情的推测， might 与 may 意思相同，但可能性更小 , 多用于虚拟语气结构中。如 :

He might have given you more help,

even though he was busy.

他或许会多给你一些帮助，即使他很忙。

在英语中，表示对过去某种情况或已发生的动作进行推测，常用“情态动词 + have + 动词 -ed 形式”表示。说话人的语气或推测的把握程度不同，使用的情态动词也不同。

1. must have done 意为“过去一定做过……”。如：

It must have rained last night, for the ground is wet.

2. can / could have done 意为“过去可能做过……”或“过去本来可以做……而没有做”， can’t / couldn’t have done 意为“过去不可能做过……”。如：

Don’t worry. They could have just f

orgotten to phone.

I could have passed the exam, but I

was too careless.

Mr Smith has gone to Beijing, so yo

u couldn’t have seen him yesterday.

3. needn’t have done 意为“本不需要做……却做了”。如：

I needn’t have written to him becaus

e he phoned me shortly afterwards.

4. ought to / should have done 表示“过去应该去做……而没有做”。 ought

not to / shouldn’t have done 表示“过去不应该做……却做了”。如：

Sam, you are too lazy. The work shou

ld have been finished last night.

You ought not to have taken the book

out of the reading room.

1. Thank you for all your hard work

last week. I don’t think we ____ it

without you. (2008 山东 )

A. can manage

B. could have managed

C. could manage

D. can have managed

2. — I’m sorry. I ______ at you the other day. — Forget it. I was a bit out of control myself. (2008 江苏 ) A. shouldn’t shout B. shouldn’t have shouted C. mustn’t shout D. mustn’t have shouted

3. — Hi, Tom. Any idea where Jane is? 　— She ______ in the classroom. I saw her there just now. (2009 重庆 ) A. shall be B. should have been C. must be D. might have been4. But for their help, we _____ the program in time. (2009 安徽 ) A. can not finish B. will not finish

C. had not finished D. could not have finished

5. He did not regret saying what he did

but felt that he _____ it differently.

(2009 江苏 )

A. could express

B. would express 　 C. could have expressed

D. must have expressed

6. — The weather has been very hot and dry. — Yes. If it had rained even a drop, things would be much better now! And my vegetables _______. (2010 北京 ) A. wouldn’t die B. didn’t die C. hadn’t died D. wouldn’t have died

7. — I left my handbag on the train, but luckily someone gave it to a railway official. — How unbelievable to get it back! I mean, someone ______ it. (2011 江苏 ) A. will have stolen B. might have stolen C. should have stolen D. must have stolen

8. Had they known what was coming

next, they _____ second thoughts.

（ 2012浙江）

A. may have

B. could have

C. must have had

D. might have had

1. Revise what you have learnt in the less

on.

2. Finish the Exercises 2-3 in Grammar

on Page 57.