Unit 5 Grammar 情态动词 ppt课件 -（2021新）人教版高中英语必修第三册.pptx

1、Modal verbsModal verbs表示说话人的语气表示说话人的语气没有人称和数的变化没有人称和数的变化basic modal verbs basic modal verbs 基本情态动词基本情态动词 Book 3 Book 3 Unit 5Unit 5Test yourself Test yourself 测一测测一测Coco, you _play with the knife, you _hurt yourself.A.wont; cant B. mustnt ; may C. shouldnt ; must D. cant ; shouldnt -Will you stay fo

2、r lunch ?-Sorry,_. My brother is coming to see me .A.I mustnt B. I cant C. I neednt D. I wontTest yourself Test yourself 测一测测一测Are you coming to Jeffs Party ?Im not sure. I _go to the concert instead.A. must B. would C. should D. might When he was there, he _go to that coffee shop after work.A. woul

3、d B. should C. had better D. might Modal verbsModal verbs情态动词体现说话者的语气、情感和态度；本身具有各种含义，但不能单不能单独做谓语独做谓语，须和主要动词的原形动词的原形一起构成谓语。情态动词没有人称和数的情态动词没有人称和数的变化变化，但有过去式有过去式。may / mightmust / have toshall / shouldwill / wouldought toneed / darecan / couldMindmap of the modal verbs modal verbsModal verbsModal verbs

4、A. necessityB. possibilityC. obligation D. request E. advice F. intentionCan you give examples of each function? Find modal verbs in previous sections and discuss their functions.需要需要 可能可能 职责职责/ /义务义务要求要求 建议建议 意图意图Modal verbsModal verbsExperience the functions_you speak English ?_you speak English ?

5、Man _live without air.Man _live without air.Can cannot CanCan I smoke here ? I smoke here ?Perhaps we Perhaps we cancan go out for a go out for a walk.walk.I m afraid I I m afraid I cantcant go with you. go with you.Can Can abilityability指有能力做某指有能力做某事事, ,意为意为”能够能够”permission permission 指请求、允许、指请求、允许

6、、建议建议possibilitypossibility指可能性指可能性CouldCould 表示过去的能力表示过去的能力 表示请求更加委婉表示请求更加委婉He could swim when he was 5. Could you lend me some money ? can / could can / could 与与 be able to be able to 的区别的区别be able to 与与can/could意义相同，但常用于意义相同，但常用于强调通过强调通过努力后能做某事，而且可用于多种时态。努力后能做某事，而且可用于多种时态。考点考点The fire spread fast

7、, but everyone in the hotel was able to get out.注意注意can can 的惯用语的惯用语On hearing the story , I cannot help laughing .On hearing the story , I cannot help laughing .You cannot be too careful with them.You cannot be too careful with them.cannot help doing sth. 忍不住做某事忍不住做某事cannot too “无论怎么样无论怎么样.也不为过也不为过

8、,越越越好越好 may &may & mightmight May I watch TV after supper? Yes, you may. / No, you mustnt. They may / might be having a meeting, but Im not sure. If that is the case, you may / might as well try.(1)句中句中may表示表示_。 否定回答时，用否定回答时，用_。(2) 句中句中may和和might表示表示_，_可能性更小。可能性更小。(3) 句中句中_，意为意为“不妨不妨”。允许或征询对方许可允许或征询

9、对方许可mustnt可能性可能性mightmay / might as well 动词原形动词原形考点考点1当句中出现当句中出现” I am afraid, I am not sure” 等表示等表示不确定含义的时候不确定含义的时候,常选用常选用may 和和might .I may go, but I am not quite sure.I may go, but I am not quite sure.I am afraid he might not come to attend the I am afraid he might not come to attend the meeting

10、today.meeting today.从语气上判断从语气上判断,may 所表示的可能性比所表示的可能性比might 大大一点一点,而而might 表示较多的怀疑表示较多的怀疑.He may be very busy now. (He may be very busy now. (可能性较大）可能性较大）He might be very busy now. (He might be very busy now. (可能性较小）可能性较小） may 表示祝愿表示祝愿;但语气较正式但语气较正式: May you succeed! May you have a good journey! might

11、 多在间接引语中表示过去的可能和允许。多在间接引语中表示过去的可能和允许。 She said that he might take her bike. 考点考点2 Would you pass me the ball, please? She said that she would try her best to help us. Each time his mothers birthday came, he would buy her a present. We will do our best to save the child. Oil will float on the water.(

12、1) 句中句中would表示表示_，比，比will更委更委婉客气。婉客气。( 2 ) 句 中句 中 w o u l d 和和 句 中 的句 中 的 w i l l 表 示表 示_。( 3 ) 句 中句 中 w o u l d 和和 句 中 的句 中 的 w i l l 表 示表 示_。请求、建议请求、建议意志、愿望和决心意志、愿望和决心习惯性动作或客观真理习惯性动作或客观真理will & would eg. I will tell you something important tomorrow. I will go swimming tomorrow. Will you marry me?

13、情态动词？！（助动词）（助动词） （情态动词）（情态动词）考点考点1Attention: would表示过去的习惯性动作时，暗示现表示过去的习惯性动作时，暗示现在仍然如此；在仍然如此；而而used to表示过去常常做某事，强调现在表示过去常常做某事，强调现在不是这样了。不是这样了。Each time his mothers birthday came, he would buy her a present.My father used to go to the office by bike when he was young.shall & should & ought to Shall 常用

14、于第一人称，表示征求对方意见或表决心常用于第一人称，表示征求对方意见或表决心Shall we dance?Shall we go by train?I shall go at once.Shall 用于第二，第三人称中，表示说话人的用于第二，第三人称中，表示说话人的意愿意志，给对方的警告或命令意愿意志，给对方的警告或命令You shall fail if you dont work hard. (You shall fail if you dont work hard. (警告）警告）He shall be punished. (He shall be punished. (威胁）威胁）用于法

15、律，条约，规章，等文件中，无论用于法律，条约，规章，等文件中，无论主语人称如何一律用主语人称如何一律用shallshall Each student shall arrive at school Each student shall arrive at school before 7:15 in the morning.before 7:15 in the morning.Attention pleaseshould 劝告，建议，劝告，建议，= ought to 期待，预测，用于表达合理的推断或明显的结果期待，预测，用于表达合理的推断或明显的结果 义务，指应该做，且有道义上的责任义务，指应该做

16、，且有道义上的责任 All visitors should / ought to register with the British Embassy. I find it astonishing that he should be so rude to you.(1) 句中句中should表示表示“_”，其同义词，其同义词是是_；在疑问句中，通常用；在疑问句中，通常用_代替代替ought to。(2) 句中句中should 有时可用于某些从句中，表示说话人惊奇、有时可用于某些从句中，表示说话人惊奇、失望等感情色彩，常译为失望等感情色彩，常译为“ _”。义务、责任、建议义务、责任、建议ought

17、 to竟然竟然；怎么会怎么会shouldShould 表示惊讶，忧虑，惋惜，意思表示惊讶，忧虑，惋惜，意思“竟然，竟会竟然，竟会” 常用常用在在Im surprised, its a pity, you cannot imagine 等结构中等结构中 I have to wait here because I have no umbrella with me. I must recite the text this morning. Must we hand in our exercise books today? Yes, you must. / No, you dont have to /

18、 you neednt. You mustnt smoke here. Your mother must be waiting for you now. Why must you always interrupt me?(1) 句中句中have to和和句中句中must均表示均表示“_”，但，但_是指说话人的主观是指说话人的主观看法，而看法，而_则强调客观需要。则强调客观需要。(2) 句中句中must 所构成的疑问句，回答的否定形式通常为所构成的疑问句，回答的否定形式通常为_或或_，意为，意为“不必要不必要”，而一般不说，而一般不说_ (句中句中mustnt表示表示“禁止禁止”)。(3) _句

19、中句中must 常表示有根据的、比较确定的推测常表示有根据的、比较确定的推测（只用于肯定的陈述只用于肯定的陈述句句），译为，译为“一定一定；必定必定”。(4) 句中句中must表示表示“_”。must & have to必须必须musthave toneedntdont have tomustnt偏要偏要；偏偏偏偏 If he dare go, Ill go with him. Tom didnt dare to do it.(1) dare作情态动词时，表示作情态动词时，表示“ _”。常用于否定句和疑问。常用于否定句和疑问句中，后接动词原形，否定形式为句中，后接动词原形，否定形式为_。(2)

20、 dare常用作常用作_ ，有，有_的变化，后面可的变化，后面可接接_ 。(3) dare 作为实义动词，有如下搭配：作为实义动词，有如下搭配： dare to do sth 敢于做某事敢于做某事 dare sb to do sth 激某人做某事激某人做某事 dare & need & had better敢敢； 敢于敢于dare not实义动词实义动词时态、人称和数时态、人称和数带带to的不定式的不定式need与与dare用法对比用法对比need dare1.情态动词情态动词+V *疑问式疑问式 *否否定式定式He need not (neednt) go.Need we do it aga

21、in?No, you neednt do it again.Dare she go out alone at night?How dare you say I am unfair?He dare not say so.2.need/dare+ to do *肯定式肯定式 *否否定式定式 *疑问疑问式式He needs to go.He doesnt need to go.Does he need to do it again?He dares to say.He does not dare (to) say.If you dare to jump into the water from here, so dare I. You had better get some sleep. You had better not talk with strangers. had better表示表示“_”，使用时常缩写为，使用时常缩写为_，无人称和数的变化，其否定式一般把，无人称和数的变化，其否定式一般把not放在放在had better之之_。had better最好最好d better后后