1、ElectricityGrammardrawYes,she can.She can draw.Can she draw?1Lookandsay!(using“can”)singNo,they cant.They can sing.Can they draw?Lookandsay!(using“can”)Lookandsay!(using“can”)No,she cant.She can dance.Can she swim?Lookandsay!(using“may”)Yes,you may.No,you cant.May I watch TV?A man is going to see hi
2、s boss.He is standing at the doorway.May I come in?Lookandsay!(using“may”)A student is going to ask the teacher a question.May I ask you a question?A boy is thirsty.He is asking his mother for something.May I have some water?Lookandsay!(using“may”)What are the rules?Well,we cant sleep in class.We mu
3、st study hard.Lookandsay!(using“must”)What are the rules?Well,we mustnt run the red traffic lights,we must obey the rules.Lookandsay!(using“must”)What do these signs mean?（You mustnt smoke here.）（You mustnt climb this ladder.）（You mustnt swim here.）（You mustnt use your mobile phone here.）Lookandsay!
4、(using“must”)A can and cannotModal verbsWe use the model verbs can and cannot(cant)to say we are able or unable to do something.Wecanuseelectricitytodomanythings.Wecannot/cantseeelectricity.Canyouthinkofanexample?Yes,Ican./No,Icannot/cant.2can be able to “能”，表示能力I can/am able to sing an English song
5、.我可以唱一首英语歌曲。表示许可或请求对方允许，意为“可以”Can I use your dictionary?我可以用你的字典吗？过去式：could 我十年前就能做到那样.I could do that 10 years ago.否定式：cannot=cant情态动词can的用法could 是can 的过去式，但表示请求许可时，could 和can 不表示时态的区别，只是could 的语气更加委婉，用could 提出的请求要用can来回答。Peter can speak English.l否定 Peter cant/cannot speak English.l一般疑问句Can Peter s
6、peak English?(一般疑问句，提前情态动词)l特殊疑问句What can Peter speak?Hi and Lo are talking about themselves.What are they saying?Read their conversation and then complete the statements below with can or cannot.1.Hi _ play football.2.Lo _ paint.3.Hi _ speak as many languages as Lo.4.Both Hi and Lo _ dance.5.Lo _ d
7、rive a car,but he _ play chess.6.Hi _ swim,but he _ play the guitar.cancancancancannotcannotcannotcannotB may and may notWe use may and may not to ask for and give permission.We also use can and cannot(cant)for the same purpose.May/CanIuseyourmobilephone？Yes,youmay/can.No,youmaynot/cant.Youmay/cantu
8、rnontheTV.Youmaynot/cannotplayinthekitchen.情态动词may的用法may表示允许may 表示许可或请求对方允许，意为“可以”，相当于can。两者的区别在于：表示请求许可时，may更能表示礼貌或敬意。May I watch TV now,grandma?No,you may not.否定式：may not意为“不可以”。may构成的一般疑问句及其回答形式如下：May I.?(肯定回答)Yes,you may/can.(否定回答)No,you may not/cant/mustnt.(注：mustnt 的语气最强，表示禁止)Benny:How are you
9、 feeling,Daisy?Daisy:Not very well.Benny:_ I get you a chair?Daisy:Yes,thanks.Benny:Im going out._ I borrow your bicycle,Daisy?MayMay/Can Daisy is not feeling well today.Benny is at home with her.Read their conversation below.Fill in the blanks with may or can.Daisy:Yes,you may.Before you go to meet
10、 your friends,can you come and see the doctor with me?Benny:Yes.I _._ I carry your bag for you?Daisy:Yes,thats very kind of you,Benny.Im ready to go._ you open the door for me?Benny:Yes,I can.Daisy:Thanks.MayCanCanC must and must notWe use must and must not(mustnt)to tell people what to do or what n
11、ot to do.Youmustnot/mustntdothat,Benny!Wemustalwaysbecarefulwithelectricity.Theymustnot/mustntplayneartheheater.情态动词must的用法must 表示规定、命令、强制，意为“必须；一定”。如：You must do your homework first.你必须先做作业。You mustnt smoke here.你不许在这里吸烟。must 的否定式为must not/mustnt，意为“禁止；不准”must 构成的一般疑问句及其回答形式如下：Must I.?(肯定回答)Yes,you
12、 must.(否定回答)No,you neednt.辨析must和have to意义用法must“必须；一定”强调客观上必须做某事have to“不得不；必须”强调主观上不得不做某事1.I must drink more water.2._3._4.I must not _5._6._I must go to bed early.I must take the medicine on time.eat cold food.I must not go out alone.I must not share cups with others.Daisy saw a doctor.The doctor
13、 told her what to do and what not to do.Help her write down the doctors instructions.drink more water go to bed early eat cold food share cups with others go out alone take the medicine on time31.We have learned how to use the modal verb can,may and must.情态动词后接动词_，没有人称和数的变化，_单独作谓语，要与后面的_共同作谓语。其否定形式是
14、在其后面直接加_。情态动词can 的用法：表示能力。构成一般疑问句时，需把can 移到_（句首/中）。肯定回答为“Yes,主语+_”；否定回答为“No,主语+_”not原形不能动词句首cancant/cannotSummary情态动词may 的用法：表示允许。may在表达这个意思时可以与can 互换使用。由may 引起的一般疑问句，其否定回答用_，_ 或 _。表示请求时，could 和can 不表示时态的区别，只是could的语气更加委婉。情态动词must 的用法：表示必须/一定。其否定形式mustnt 表示_。由must引起的一般疑问句，其否定回答要用_。may notcant/cannot
15、mustnt禁止neednt一、用本单元所学的情态动词填空。1.Kate,you have won the English competition!Oh,it _ be true.I made a lot of mistakes in it.2.You _ talk to your grandparents like that.Its impolite.3.We _ wash our hands before meals.It is good for our health.cantmustntmust4.Excuse me,_ you tell me the way to the neares
16、t park?5.You _ go with us to the zoo if you want to.6.I _ speak Chinese very well,but I _ speak French at all.cancan/maycancant4二、翻译下列句子。1.门锁了。他不可能在家。The door is locked.He _ be at home.2.我的手表停了，肯定有毛病。My watch doesnt work.There _ be something wrong with it.3.我可以借用你的尺子吗？当然可以。但是你必须明天还给我。_ I borrow your
17、 ruler?Of course.But you _ return it to me tomorrow.cantmustMaymust三、选择最佳答案填空。()1.If you feel tired,you _ sit on this chair and have a rest.A.mustB.canC.needD.cant()2._ I watch TV now,Mum?I finished my homework.Yes,you _.A.Must,need B.May,can C.Need,need D.May,mustBB()3.He _ see the words on the blackboard because he sits far away.A.mustnt B.may not C.cant D.neednt()4._ I do all the housework now?No,you _.You can do it later.A.Must,mustnt B.Must,cant C.Must,may not D.Must,needntDC
