高中情态动词课件大全.ppt

3. can/could have done “本可以，本来可能 已经”用于肯定句中，表示对过去发生的事 情做出的判断.
e.g.你本来可以考的更好。 You could have had a better mark.
may/might
1.may/might表示推测时，只能用于陈述句， 表示对现在或将来要发生的动作把握不大。 e.g.她们明天可能会到这里来。
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needn’t +have done表示做了本 来不必去做的事。
1.She needn’t have gone to the station yesterday.
昨天她本不必到火车站去的.（昨天她去了） 2.You needn’t have bought it. 你本可不必买它的。 （你买了）
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should/ought to+have done用于 肯定句时，表示“本该做某事而 实际上没做”，用于否定句时， 则表示“不该做的事反而做了”。
1.You should have told him a week ago. 你本来应该在一周前告诉他的。 2.You ought not to have taken the magazine
(rain) 4. Your mother __m__u_st__h_a_v_e_b_e_e_n__lo_o_k_i_n_g_ for you.
你妈妈一定一直在找你。
5. Philip _m__a_y_(_m_i_g_h_t_)_h_a_v_e_b_e_e_n__h_u_r_t seriously in the car accident. 菲利普可能在车祸中受了重伤.
can, ; V.
+ have done
+ be doing
可以用not表示“可能不”
+V.
+ V.
+ have done
+ be doing
+ V.
+ V.
+ have done
+ be doing
因must后是系动词 be
1.Judging from his accident, he must be from the south, isn’t, he?
They may come here tomorrow. 他们可能还在等我们呢。
They may be still waiting for us.
3.might/may have done,表示对过去发生的动 作进行可能性推测。
e.g.他可能去医务室了。
He may have gone to the clinic. 他可能已经从报纸上知道这个消息了。
1. I could have passed my exam easily, but I made too many stupid mistakes. 我本来能够轻易通过考试，但我犯了太多不该 犯的 错误。
2.You could have reported to me earlier. 你本该早点告诉我的。
6. ---Linda has gone to work, but her bicycle is still here. ---She _m__a_y_(_m_i_g_h_t_)_h_a_v_e_g_o_n_e__ (go) by bus.
7. Mike _c_a_n_’_t_h_a_v_e_f_o_u_n_d__ his car, for he came to work by bus this morning. 迈克一定还没有找回他的车，因为早上他是坐 公共汽车来上班的。
Practice 2:表示推测——情态动词的重要用法. 1. You must be Mr Smith----I was told to expect
you here. 2. He must have known what we wanted. 3. We may have read the same report. 4. He can’t have slept through all that noise. 5. There’s someone outside----who can it be? 6. What can they be doing? 7. These pills might help to cure your disease. 8. You could be right, I suppose.
因must后是实意动词like
2.Tom bought a lot of apples. He must like eating apples, didn’t he?
3.It is eleven o’clock at night and the lights are off. They must be sleeping now,aren’t they?
对现在或将来情况推测：must +动词原形。 must只能用于肯定。否定和疑问分别用can’t 和can。 e.g. He must tell a lie.
Can he tell a lie ? He can’t tell a lie. *must-should/ought to –may-might/could+do 可能性依次减弱
3.must +have done 表示对过去发生的事情作 出的肯定判断 e.g.他们在玩篮球， 他们一定完成了作业。
They are playing basketball, they must have finished their homework.
路是湿的。昨天晚上一定下雨了。
The road is wet. It must have rained last night.
Grammar
modal verbs
can could may might shall should must will would 情态动词 ought to have to dare (daren’t) need (needn’t) used to
表示推测 不表示推测
情态动词有一定的意义，但没有人称和数的 变化，不能独立使用，它和后面的动词构成 谓语．
must后接的是be sleeping，是对正在进 行的情况推测
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1.We must have learned 2,000 words by the end of last term, hadn’t we?
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
2.It must have rained last night, for the road was very muddy，didn’t it?
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
3.He must have gone to Beijing, hasn’t he?
若句中不含任何时间状语， 用现在完成时完成反意疑问句
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1. I don't know where she is, she __m__a_y__ be in Wuhan. 2. At this moment, our teacher __m_u_s_t_b_e__m_a_r_k_i_n_g_ our exam papers. 这时，我们老师想必在批改试卷。 3. The road is wet. It _m__u_s_t _h_a_v_e_r_a_i_n_e_d_ last night.
out of the reading room. 他不该、把杂志带出阅览室的。
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might（不用may）+have done表示 “本来可能…”，但实际上没有发生的事。 另外，还可表示“本来应该或可以做某 事”之意，含有轻微的责备语气。
1.You might not have told her. 你本可以不告诉他的。（事实上你告诉他了） 2. You might have come earlier. 你本可以早点来的。（但没有这样）
She couldn’t be telling lies.
2. can/could have done 对过去发生行为的可 能性进行推测:
刚才我还看见他了， 所以他不可能出国的。 I saw him just now so he couldn’t have gone abroad.
门是锁着的， 所以她不可能在家。 The door was locked. She couldn’t have been at home.
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巩固练习
1.Oh, I’m not feeling well in the stomach. I ____ so much fried chicken just now.
He might have read about the news in the newspaper.
2. should 的用法 用于表达合理推断。 e.g. It is three o’clock, the football
game should begin now. Mary took dancing lessons for years,
1.--Is John coming by train?
--He should, but he ____ not. He likes driving
his car.
(2002高考题）
A. must B. can C. need D. may
2.It has been announced that candidates(候选人)
she should be an excellent dancer.
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表示推测——情态动词的重要用法.
情态动词
对将来
肯定的推测
+ V.