定义情态动词学课件.ppt

1、情态动词modal verbs华南师范大学外国语言文化学院华南师范大学外国语言文化学院 周巧欣周巧欣 杨锦杨锦page 10 para 1 line 4By now his restaurant ought to be full of people.line 7Nothing could be better.line 9Something terrible must have happened if Li Chang was not coming to eat in his restaurant as he always did.para 3 line 26Perhaps he should

2、go to the library and find out.para 4 line 33They would become very tired.Reading the book?ought to、could、must、should、would 是什么呢？语法特征巩固练习定义具体用法情态动词modal verbs定义 情态动词（Modal verbs）本身有一定的词义，是表示说话人的某种情感或语气，对某一种动作或状态的态度的单词。什么是情态动词？常见的情态动词有：can,could,may,might,should,shall,need,would,ought to等语法特征情态动词的语法特

3、征2.1.情态动词在句中放在谓语动词之前,谓语动词前若有助动词,则在助动词之前,疑问句中,情态动词则在主语之前。例：Nothing could be better.Something terrible must have happened if Li Chang was not coming to eat in his restaurant as he always did.Why could he get the job?情态动词无人称和数的变化，即情态动词不会因为人称和数量的区别而产生变化。例：By now his restaurant ought to be full of people

4、.By now his restaurants ought to be full of people.3.情态动词的语法特征4.5.情态动词除ought,have外，后面只能接不带to的不定式。例：By now his restaurant ought to be full of people.They would become very tired.否定式构成是在情态动词后面加“not”。例：You shouldnt come here.个别情态动词有现在式和过去式两种形式,过去式用来表达更加客气,委婉的语气,时态性不强,可用于过去，现在或将来.常见情态动词的具体用法 can和could1.

5、表示能力：会；在表示过去的能力时用could例：I can swim.I could not read such an easy book when I was seven.2.表示允许，许可。此时could不表示时态，而是比can在语气上要客气些例：Could I read your book?-Yse,you can.could提问，答语用can3.表示推测，多用于疑问句与否定句中。在这里，can与could没有时态的区别，只有可能性大小的区别。can表示的可能性比could大例：He cannot be at home.他不可能在家。Can he be ill at home？他会是生病

6、在家吗？may和might1.表示请求、许可，常译为可以。口语中可以用can或could代替may，但在正式场合用may例：May/Might/can/could I have a talk with you?2.表示推测，可译为“可能，也许”；一般情况下，might表示的可能性极小；疑问句表推测时，一般不用may而用can例：The light isnt on.It may/might be broken.3.可用于祈使句，表示祝愿例：May you be happy.must和have to1.must和have to表示必须时，意思相近，但用法不同。（1）must表示主观看法，have

7、to表示客观必要 例：I must study hard.(发自内心)I have to study hard if I want to have a good job.(外界因素逼迫)（2）must只有一种形式，have to有多种时态 例：They had to put off the sports meeting due to the bad weather.（3）must和have to的否定式意思完全不一样 例：You mustnt tell anyone the secret.(mustnt表示禁止)You dont have to tell me the secret.(dont

8、 have ton=dont need to)must和have to2.must表示推测时，肯定程度比may,might大得多，一般只用于肯定句例：He must be very lazy for his desk is untidy.3.must有时可以用来表示“偏偏”例:When I was taking a nap,a stdent must knock at my door.should3.表示义务，译为“应该”（某件事宜于做），用于各种人称例：Children should obey their parents.2.常与why,what,how等疑问词连用，表示意外、惊讶例:I d

9、ont know why you should think I did it.1.表示推测，可译为“可能，照说应该”例：It should be fine tomorrow.The film should be very good as it is starring first-class actors.情态动词+have done1.maymight+have done表示对已发生的动作或存在的状态进行不肯定的推测，might语气稍弱一点儿，只能用于肯定句和否定句中，表示过去可能做过某事或过去可能没做过某事。例：You might have read about it in the pape

10、rs.你可能在报上已经看过这个消息了。3.must+have done只用于肯定句中，表示对过去发生的事情或状态进行肯定的推测，意为过去一定做过某事。例:When I was taking a nap,a stdent must have knocked at my door.2.cancould可用于否定句中，即cant have done couldnt have done，表示对过去发生的事情或状态的肯定的推测，意为过去不可能做过，肯定没做过。例：My sister met him at the theatre last night,so he couldn t have attende

11、d your lecture.巩固练习practice1.-Where is Emma?-I cant say it for sure where she is,but she _ be out shopping.A.can B.should C.must D.may 2.The room is in a terrible mess;it _ cleaned.A.cant have been B.couldnt beC.may have been D.would be3.-When can I come for the photos?I need them tomorrow afternoon.-They _ be ready by 12:00.A.can B.should C.might D.need DABTHANKS！