高一英语下情态动词PPT课件

（一）否定句 had better, should, ought to用于否定句时， 否定词均位于其后，具体形式为： had better not do, shouldn't / should not do, oughtn‘t to do。 例1此时你最好别出发。： You had better not start at this time. 例2： 她不应该浪费时间。 She oughtn't to waste time.
1.You should have told him a week ago. 你本来应该在一周前告诉他的。
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）
（二）一般疑问句 had better, should, ought to用于一般疑 问句时，分别将had, should, ought提至 句首。 例1： 他最好立即出发吗？ Had he better start early at once? 例2：你应该这么做吗？ Should you do like this? 例3： 他应该去那里吗？ Ought he to go there?
巩 固 练 习
1.Oh, I’m not feeling well in the stomach. I B ____ so much fried chicken just now. A. shouldn’t eat B. shouldn’t have eaten C. mustn’t eat D. mustn’t have eaten 2.---Why hasn’t Jane arrived yet? ---She ____ B again in the morning? A. shouldn’t have overslept B. may have turned off the alarm clock C. must have no one t o call her D. should have someone to wake her up 3.---Did you go to the movie the day before yesterday? ----No. We ___, A but we decided not to. A.should have gone B. could go C. should go D. could have gone
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）
4.As it turned out to be a small house party, we ____ D so formally. A.needn’t dress B. didn’t have to dress up C. Might not have dressed up D. needn’t have dressed up 5.I’m rather surprised you haven’t reported him to your teacher. In my opinion, you C ___ this as soon as you found out he was cheating. A. must have done B. might have done C. should have done D. could have done
句型 时态 动词 情态动词dare 实义动词 dare 肯定句 现在时 dare do dare/dares to do 过去时 dare do dared to do 否定句 现在时 daren’t/dare not do do/does not dare (to) do 过去时 dared not do did not dare (to) do 疑问句 现在时Dare he do? Do you/Does he dare (to) do? 过去时 Dared he do? Did he dare (to) do ?
可兼做行为动词的情态动词：need 、 dare 1.作为情态动词用，常用在否定句和疑问句中。 Dare (need) +S +V S + daren’t (needn’t) +V I daren’t walk through the forest at night. Dare you walk through the forest at night? You needn’t return the book now. Need he go yesterday?
D 2.I wonder how he____that to the teacher. A. dare to say B. dare saying C.not dare say D.dared say
4.As it turned out to be a small house party, we ____ D so formally. A needn’t dress B. didn’t have to dress up C. Might not have dressed up D. needn’t have dressed up
had better(最好), should(应该)与ought to （应该）均为提建议、阐述观点的情态动词， 其后接动词原形。should 比had better语气强， ought to语气最强。一般情况下should与 ought to可通用。 例1：你最好立即去那里。 You had better go there at once. 例2：你应该努力工作。 You ought to / should work hard.
2.作实义动词用，常用在肯定句中, 有人称、 时态、和数的变化 He needs to go there himself. He has grown up,we don’t need to worry about him.
3.Sth (sb) need( want, request)+ doing/ to be done The house needs cleaning/ to be cleaned The boy needs sending to the hospital at once.
Nobody need to be afraid of catching the disease. Nobody need be afraid of catching the disease.
These dishes need be cleaned carefully.
These dishes need to be cleaned carefully. These dishes need cleaning carefully.
Grammar
情态动词
非推测性情态动词shall, will, must, mustn’t, should, would的用法 情态动词must, can/could, may/might, should/ought to表猜测的用法 情态动词could, should/ought to, may/might , needn’t+ have done 表 示假设的用法 情态动词的一些惯用法
Biblioteka Baidu
can’t, couldn’t
+V.
疑问的推测
+ V.
+ have done
can, could
•Must +have done 表示对过去已经
发生的行为进行推测，意为“想必/准 是/一定作了某事”。
1.We must have learned 2,000 words by the end of last term. 到上学期为止我们一定学了有两千个单词 。 2.He must have gone to Beijing. 他一定已经去北京了。
例2： 你应该认真学习，是吗？
You should study hard, shouldn't you? 例3： 你上课不应该讲话，是吗？ He oughtn't to speak in class, ought he?



1．The flower is dead. I _______ it yesterday. C A．should water B．must water C．should have watered D．mustn’t have watered 2．What time ought I _______? D A．arrived B．arriving C．arrive D．to arrive 3．He _______ speak to his mother like that. A A．ought not to B．doesn’t ought to C．not ought to D．ought to not A 4．I don’t think we’d better _______ it any more. A．discuss B．discussing C．to discuss D D．discussed 5．You ought to _______ him, but you didn’t. A．help B．helped
表示推测——情态动词的重要用法.
情态动词 肯定的推测 对将来 + V. 常见must be + V. 对现在 对过去 + V. + have done + be doing
must
可能的推测
may, might
否定的推测
+ V. + have done + be doing 可以用not表示“可能不” + V. + be doing + V. + be doing + have done
1.判断正误: How dare you say such a thing? How dare you to say such a thing?
He daren’t to speak English before such a crowd, did he?
He daren’t speak English before such a crowd, dare he?
（三）反意疑问句 陈述句谓语动词含 had better, should, ought to时，反意疑问句 为：had, should与ought+主格人称代词或 hadn‘t, shouldn’t, oughtn‘t+主格人称代 词。 例1：你最好别回家，是吗？
You had better not go home, had you?
could(不用can)+have done,在肯定 句中表示“本来能够…而没能…”， 具有婉转的批评和责备之意。
You could have told me earlier. 你本该早点告诉我的。
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”。
•can/could+have done表示对过去
的行为的怀疑和不肯定，通常用在否 定句和疑问句中。
1. Can they have won the basketball match? 他们可能赢了篮球赛吗？ 2. It couldn’t have been Mr. Green. He has gone to New York. 那不可能是格林先生的，他已经去北京了。