情态动词定义：情态动词用于表示期待、估计某事的发生。规则：除了ought和have之外，其他的情态动词只能接动词原形变化：无人称和数的变化包括：can,could,may,might,must,haveto,shall,should,will,would,need,oughttodare•第一组：can与couldcan=beabletodosth但区别在于，beabletodo有人称、数的变化，而且意思是“通过努力做成的事”eg.(try/manage)could在疑问句中表示委婉语气canyoutellmeyourname?couldyoutellmeyourname?exercise1、Jane____cometoseeustomorrow,butsheisnotverysure.A.mayB.canC.hastoD.must2、They____dowellintheexam.A.canbeableB.beabletoC.canabletoD.areableto3、--MayItakethisbookout?--No,you____A.can'tB.maynotC.needn'tD.aren'tADA•第二组：may/might•表示可能，也许，可以。偏重不太确定may的可能性大于might搭配：mayaswell最好eg.Youmayaswellgotoschool.•第三组：must/mustn't/can/can'tmust表示有把握的推测eg.她肯定在看书表示必须时，VShavetomustn't表“一定不要，禁止做”。由其引导的疑问句，肯定回答为must，否定回答为don'thaveto或者needn'tcan't表不能，当表猜测时，意为“不可能”搭配：can'thelpdoingsthexercise1、--He____beintheclassroom,ithink.--No,he___beintheclassroom,isawhimgohomeaminuteago.A.can;maynotB.must;maynotC.may;can'tD.may;mustn't2、Hisarmisallright,he___goandseethedoctor.A.hasnotB.don'thavetoC.haven'ttoD.doesn'thavetoCD•第四组：maybe/maybemaybe中的may是情态动词，be为动词原形，通常在句子中，表可能是。eg.Hemaybewrong,buti'mnotsure.maybe是adv.通常在句首，表示大概也许。=perhapseg.Maybeheisright.•第五组：need/dare•均为既能做情态动词，也可以是实义动词•当做情态动词时否定形式为needn't疑问形式为needi....?(回答时肯定用must.否定用needn't)•当做实义动词时有人称、数的变化，后接todo不定式•heneedn'tseeadoctor.情态动词•hedoesn'tneedtoseeadoctor.实义动词•hedoesn'tplaytheguitar.实义动词exercise1、--Shalligetonemoreappleforyou,Dad?--Thanks,butyou____,iatetoomany.A.maynotB.mustnotC.can'tD.don'thaveto2、It’snotfar.We______takeataxi.A.needn’tB.can’tC.mustn’tD.couldn’tDA•第六组：should/shall•should表“应该”，用于劝告、建议、责任等eg.Youshouldturnright.=oughtto表“竟然”，用于表示惊讶，肯定句。eg.Heshouldpasstheexam.shall表建议时，多用一、三人称eg.Shallwegoforawalk?表警告和命令时，多用二、三人称eg.Nooneshallbringphonesintheexam.
