英语高二第二学期unit 4 grammar

1.A snail ________________ must have crawled (crawl) these marks. might have touched (touch ) the 2. An elephant __________________ paper with its nose. 3. A panda ___________________ could not have made ( make) theses marks.
• can have done • 通常只用于否定句和疑问句 • 。用于否定句时表否定推断，推测肯定没 • 做；用于疑问句时意为“难道真的做了吗” ，表示怀疑。例如： • Can he have done such a foolish thing? (= Is it possible …?) 他会做这样的傻事吗？（表怀疑） • He can't have taken it home. 他不可能把它带回家了。（表不可能）
We needn’t have taken the umbrella. __________________________________ It’s sunny now. 我们本不必带伞的，现在天气很好。
A strange exhibition called Animal Art 1. Which animal do you think made these works of art? Write three sentences about each one.
• could have done • 可用于肯定句、疑问句和否定句。用于肯定 • 句既可以表示过去能够做而实际未做，有惋 • 惜、遗憾或委婉批评之意，也可以表示对过 • 去动作的推测；用于否定句和疑问句的情况 • 与can have done相同。例如： • You could have done better, but you • didn't try your best. 你本可以做得更好，但是你没有尽力而为。 （表惋惜） • This glass is cracked. Someone could have dropped it. 这个玻璃杯破了。可能是谁把它掉在地上了 。（表推测过去）
• Could he have left the work unfinished? 他会丢下工作不干了？（表怀疑） • He couldn't have checked out so early. 他不可能这么早就离开了。（表不可能）
Van Gogh worked in an art dealer's company, but he must have disliked it, because he left. To talk about something that we think certainly happened, we use: must + have + past participle must have done表示对过去发生事情或行为的 推测，语气非常肯定，可译为“想必一定”或 “准是”。该结构只用于肯定句。
may have walked 1. A cat _________________(walk) on the paper. 2. A small dog _______________ must have done (do) this. could not have made make) 3. An elephant ___________________( these marks.
must have done的反意疑问句有三种情况：
①若句中含有过去的时间状语，用一般过去
时完成反意疑问句。
②若句中含有过去完成时的时间状语，用过
去完成时完成反意疑问句。
③若句中不含任何时间状语，用现在完成时 完成反意疑问句。
1.We must have learned 2000 words by the hadn’t we end of last term, __________? 2. He must have gone to Beijing, _________? hasn’t he
1.The ground is very wet. _______________________________________ It must have rained last night.
地面很湿，昨天晚上一定下雨了。
2. You ________________________________. must have mistaken Anna for her sister 你一定是把安娜当成她妹妹了。
The light isn’t on. He can not / may not / might not / could not be studying.
The light is on. Can/Could he be studying now?
Practice
What do you think the pig is doing? He must / may / might / could be doing morning exercise.
?
He
might be Liu Xiang. could
He must be Wen Zhang.
Oh, yes. He is Wen Zhang.
Revision
1. 肯定句中，表示对当前行为、状态、情况 的推测用：
must / may / might / could + do/be
否定句用
can not, could not, may not, might not. 疑问句用 can, could
Painting the world
Grammar
Revision
1. 超过 2. 听说 more than
hear of
3. 停止做某事 stop doing sth. pay.. for… 4. 为…付款 5. 寻找
6.担当, 充当 looel with as well
3. The ground is very wet. It must have
didn’t it rained last night, _________?
Other modal verbs
• should / ought to have done • shouldn’t / ought not to have done • needn’t have done
1. They can’t ___________________, have gone to work as it’s weekend. 他们不可能去工作了，因为是周末。
2. Somebody must have opened the cage. The lion ______________________on its own. couldn’t have escaped 一定是有人打开了笼子，狮子是不可能自 己跑出来的。
may have made (make) these marks. 1.A dog ________________ might have done (do )this. 2. A cat __________________ could not have made ( make) theses 3. A spider ___________________ marks.
Van Gogh couldn't have painted this --- it’s too new.
To talk about something that was impossible, we use:
could not/cannot + have + past participle To talk about something that was possible, we use: could + have + past participle can / could have done是对过去发生事情或行为的 推测，用于否定句和疑问句，could的语气比较 委婉，意为“可能已经”。
Can they be playing now?
Yes, they must / may / might / could be playing now.
No, they can not / could not / may not / might not be playing now. They must be fighting now.
To talk about something that was possibly (not) true, we can use: may / might + (not) have + past participle may / might have done表示对过去行为的推 测，可译为“可能已经”或“想必已经”。
7.和…吵架
8. 也
Modal verbs + have + past participle
Look and guess using “can’t,might/could,may,must”
Who is the man?
He can’t be Bill Gate. He may be Liu Xiang.
猜测语气：
must > may > might / could
2. 表示对此时此刻正在进行的动作的推测用：
must / may / might / could + be doing
The light is on. He must / may / might / could be studying.