8.情态动词表推测课件.ppt

He be Curnane!He be thinking.He be a common boy.情态动词表推测情态动词表推测mustmightcant表推测的三种句式表推测的三种句式The light is on,so somebody _ be at home.mustThe light is on,so my sister _ be at home.may/might 1.在肯定句中一般用在肯定句中一般用must,may/might，语气气逐逐渐减弱。减弱。常用于表推测的情态动词常用于表推测的情态动词will wouldought toshould（一定一定）（可能可能）（很有可能很有可能）（很有可能很有可能）（应该，很有可能应该，很有可能）（应该，很有可能应该，很有可能）（可能可能）（可能可能）（可能可能）肯定肯定推推测测最最 强强最最 弱弱mustmightcancouldmayIts sunny.It _ rain.cant表推测的三种句式表推测的三种句式 2.在否定句中用在否定句中用cant/couldnt(不可能不可能)，may not/might not(可能不可能不)。He _ know how to answer this question./might notmay not常用于表推测的情态动词常用于表推测的情态动词（禁止禁止,不许不许）（可能可能）（肯定不肯定不,不可能不可能）（肯定不肯定不,不不可能）可能）（可能（可能不不）否否定定推推测测最最 强强最最 弱弱must notmight notcantcouldntmay not（不不用于用于推测推测）表推测的三种句式表推测的三种句式 3.在疑在疑问句中，一般只使用句中，一般只使用can/could。she have finished her homework?your sister be at home now?CouldCan【口诀口诀】can不肯，may/could/might不问，must不否问注注：can表示推测时，不用于表示推测时，不用于肯定句肯定句；may/might/could表示推表示推测时，不用于疑问句测时，不用于疑问句；must表示推测时，不用表示推测时，不用于否定句或疑问句。于否定句或疑问句。情态动词表推测的三种时态情态动词表推测的三种时态He _ to music.对现在或一般情况的推测“情态动词+be”“情态动词+be doing”“情态动词+动词原形”must be listing He _ at home now.The light isnt on.cant beHe _ in his office.may work情态动词表推测的三种时态情态动词表推测的三种时态She _ very happy when she opens the door.对将来推测，对将来推测，“情情态动词+动词原形原形”must be情态动词表推测的三种时态情态动词表推测的三种时态The ground is wet.It _ yesterday night.对过去或已经完成的推测，对过去或已经完成的推测，“情态动词情态动词+have+过去分词过去分词”may have rained表对已经发生的事情的推测，意为“一定，想必”，在句子中表示的是一种肯定的推测。这种结构一般只用于肯定句。对过去推测的几组用法对过去推测的几组用法1.must have done否定形式：否定形式：cant(couldnt)have doneThey out,because the light is still on.He didnt hear the phone.He asleep.“不可能，肯定不会不可能，肯定不会”must have beencant have gone表表对过去的时间里可能发生的事情的推测，对过去的时间里可能发生的事情的推测，一般只用于否定句和疑问句一般只用于否定句和疑问句。对过去推测的几组用法对过去推测的几组用法2.can/could have doneHe cant have finished the work so soon.用于用于肯定句中，常用来表示本来可以完成而肯定句中，常用来表示本来可以完成而实际未完成的动作实际未完成的动作。We could have walked to the station,it was so near.“本来能做本来能做.(而而实际上没实际上没做做)”1)表对已经发生的事情不太肯定的推测，意为“可能已经，或许已经”对过去推测的几组用法对过去推测的几组用法3.may/might have done2)虚拟用法：表可以做，但却没有做。If we had taken the other road,we might have arrived earlier.He might have given you more help,but he was very busy.推推测测三三种句式种句式否否定定肯定肯定疑问疑问常用于表推测的情态动词常用于表推测的情态动词否否定定肯定肯定情态动词情态动词表表推测的三种时态推测的三种时态将来将来现在现在/一般一般过去过去/完成完成几组几组对过去对过去的的推测推测can/could have donemust have donemay/might have doneExercise:1.Whose earrings are these?They _ be Marys.She wears earrings sometimes.2.Carls _ come to the party tonight,but Im not sure.3.The telephone is ringing,but nobody answer it,he _ be at home.4.-Is this Lan Qiangs boxing glove?-Yes,it _ be his.This is his name on the back.5.Youd better take an umbrella.It _ rain this afternoon.may/could/might must may/might/could cant may/might/could 6.Its the library!So you _ know shouting is not allowed here.7.-Have you decided where to spend your summer holiday?-Not yet.We _ go to Qingdao.8.-Is Jessica giving us a speech this evening?-No,it _ be her.She has gone to Japan.9.-What will the weather be like tomorrow?-It _ be rainy,cloudy,or sunny.Who know?10.You _ be tired after playing sports for a long time without a rest.mustmaycantmightmust