1、单个情态动词讲解1. can (could) 1).表示能力，意为“能，会”，用can,could,beableto均可，could是can的过去式。区别是：can只有过去时could，而beableto有多种时态。Johncanspeakthreeforeignlanguagesfluently.Johncouldswimwhenhewasfour.IregrettedthatIhadn’tbeenabletodrivehimhome.WillyoubeabletohelpmelearnEnglishtomorrow?明天你
2、能帮助我学习英语吗？2）表示可能（理论上或是逻辑判断上）。The temperature can fall to –60℃。气温可降至—60℃Anybodycanmakemistakes.表示推测或可能性，常用于否定句和疑问句Canhebeatschool?TodayisSunday.Hecan'tbeatschool. Thereisnolightintheroom.Canshehavegonetobed?对过去的推测Shecouldhavegoneoutwithsomefriendsyesterday.Itwassilly
3、tothrowtheTVoutofthewindow.Itcouldhavehitsomebody.Youarelateagain.Youcouldhavegotupearlier.3）表示请求或许可（Could比Can更加客气，can比may更正式）CanIparkmycarinfrontofyouroffice?Can I have a look at your new pen? He asked whether he could take the book out of the reading—room. CouldIu
4、seyourbikenow?----Certainly.Goahead.Yes,youcan4）表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。Where can (could) they have gone to? 他们会去哪儿了呢？He can´t (couldn´t) be over sixty. 他不可能超过六十岁。How can you be so careless? 你怎么这么粗心？5）比较委婉客气地提出问题或陈述看法。Can (Could) you lend me a hand? 帮我一把好吗？I´
5、m afraid we couldn´t give you an answer today. 恐怕我们今天不能给你答复。2.mayandmight1)表示可能性;表不太可能的推测,might可以指过去时间，也可以指现在时间，但语气更加不肯定,may/mighthavedone对过去的揣测Helenmaygoonthetripwithus,butsheisn’tquitesureyet.They might be having a meeting, but I´m not sure. Hemaybebusythesedays.S
6、he may not know about it. He was afraid they might not agree with him. Yourmathteachermay/mightbeinhisoffice.注意：用may表示推测一般不用于疑问句，在疑问句中通常用can来代替。①Canhebeathome?他可能在家吗？②Canitbetrue?这可能是真的吗？--Itmaybe,ormaynotbe.2)表示允许和请求might不表示过去时，而是表示口气比较婉转。Youmaytakewhateveryoulike.
