Unit 5 情态动词 过去将来时课件 高中英语人教版（2019）必修第三册.pptx

Unit 5 The Value of MoneyDiscovering Useful Structures Model Verbs情态动词一、情态动词的特征情态动词有一定的意义，表示或暗示某种情绪或态度，表示可能、建议、愿望、必要、允许、能力等。 大多数情态动词有多个意义。2. 情态动词没有人称和数的变化，即不随主语的不同而变化。 3. 情态动词不能独立使用，须后接动词原形，一起构成谓语动词。4. 情态动词除ought和have外，后面接不带to的不定式。(dare)5.情态动词没有非谓语形式，即没有不定式、分词等形式。二、情态动词的分类can/could, may/might, ought to, must1.只作情态动词的：2. 可情态可实义的： 3. 可情态可助动词的: 4. 相当于情态动词的: need, dareshall/should, will/wouldhave to, used toExampleNecessityPossibilitiesObligationRequestAdviceIntentionWe can discuss it now.You must do it at once.Would you please pass me the salt?You needn’t have stayed.You ought to help him.I would rather do it myself.cancan表示推测can表推测时一般用于否定句和疑问句中(could一般无此限制)。表示对过去发生的行为怀疑或不肯定时, 常用“can/could+have+过去分词”的否定或疑问形式。It can’t/couldn’t be true. 那不可能是真的。Can/Could he have heard the news? 他可能听说过这个消息了吗? can表示客观的、一时的情况, 意思是“有时候会”。The weather in Jiangxi can/could be very cold in winter. 江西冬季可能很冷。表示惊异、怀疑, 不相信的态度(主要用在否定句、疑问句或感叹句中)。How can you be so careless! 你怎么那么粗心呀! (could是can的过去式，语气更委婉)　cancould①He can play golf now, but he couldnt last year.②Walking with a stranger can be highly dangerous.③- Can/Could I have a look at your new laptop?我可以看看你的新笔记本电脑吗?一Yes，you can./No，you cant.可以。不可以。④That girl under the tree cant be Jenny- shes in the classroom now.⑤Someone is knocking at the door. Who can it be?⑥You cant be careful enough.能力可能性许可可能可能再……也不为过maymight　①—May I watch TV after supper?—Yes，you may./No，you mustn’t.②They may/might go to the party，but I’m not sure.③If you are interested in the match，you may/might as well try.(1)①句中may表示______________________。否定回答时，用____________。(2)②句中may和might表示____________，____________可能性更小。(3)③句中______________________________，意为“不妨”。允许或征询对方许可mustn’t可能性mightmay/might as well＋动词原形musthave to　①I have to wait until the rain stops because I have no umbrella with me.我不得不在这儿等到雨停，因为我没带伞。(强调客观需要)②I must recite the text this morning.今天早上我必须背会这篇课文。(强调主观意志)③—Must we finish our homework today?—Yes，you must./No，you don’t have to/you needn’t.④You mustn’t park here.⑤Your