1、.may/mightaswell+V原形最好“不妨”“還是的好”情態(tài)動(dòng)詞(ModalVerbs)概念和特征表示說(shuō)話(huà)人對(duì)某一動(dòng)作或是狀態(tài)的態(tài)度的動(dòng)詞。情態(tài)動(dòng)詞具有一定的詞義，但不能獨(dú)立作謂語(yǔ)，要和后面的動(dòng)詞原形一起作謂語(yǔ)，它沒(méi)有人稱(chēng)和數(shù)的變化，具有助動(dòng)詞的作用，即用來(lái)構(gòu)成否定句、疑問(wèn)句及用于簡(jiǎn)單回答。類(lèi)型只用作情態(tài)動(dòng)詞的：mustcan/couldmay/mightoughtto既可作情態(tài)動(dòng)詞也可作實(shí)義動(dòng)詞的：needdare可作情態(tài)動(dòng)詞也可作助動(dòng)詞的：shall/shouldwill/would具有情態(tài)動(dòng)詞特征的動(dòng)詞短語(yǔ)：havetousedtowouldratherhadbetter用法Ca

2、n/Could.表示能力，相當(dāng)于beableto。CanyouspeakEnglish?Hecouldswimwhenhewas5Can只能用于一般現(xiàn)在時(shí)和一般過(guò)去式，而beableto可用于各種時(shí)態(tài)。Shehasbeenabletoplaythepianofor3years.表示征求意見(jiàn)，許可，could比can的語(yǔ)氣要委婉，相當(dāng)于may。CanIsmokehere?Yes,youcan./No,youcant.Sheaskedwhethershecouldsmokehere.Youcangowithusifyoulike.表示推測(cè)，can比could可能性大，用于肯定句、否定句、疑問(wèn)句均可

3、。Accidentscanhappenonsuchrainydays.Itcantbetrue.Can/could+V原形表示對(duì)現(xiàn)在的狀態(tài)特征推測(cè)Can/could+bedoing表示對(duì)正在進(jìn)行的動(dòng)作的推測(cè)Can/could+havedone表示對(duì)過(guò)去的推測(cè)Hecantbeathomenow.Hecanbestudyingnow.Hecouldhavegonetoschool.ItsSunday.但是情態(tài)動(dòng)詞表示推測(cè)時(shí)其反義疑問(wèn)句應(yīng)根據(jù)動(dòng)詞的實(shí)際事態(tài)而變化。.couldhavedone本能夠，本可以Youcouldhaveborrowedmycar.Iwasntusingit.Youcould

4、havecomeearlier.表示說(shuō)話(huà)人的驚異、懷疑、不相信的態(tài)度（主要用于否定句、疑問(wèn)句和感嘆句中）Canhebeworkingtillsolate?Howcanyoubesocareless!May/Might.表示征求意見(jiàn)，請(qǐng)求和許可。MayIsmokehere?Yes,youmay.No,youmustnt/dbetternot/cant.Youmaysmoke.表示推測(cè)，may可能性比might大，不如can語(yǔ)氣強(qiáng)烈。可能也許，通常用于肯定句中。may/might+v原形表示對(duì)現(xiàn)在的狀態(tài)特征推測(cè)may/might+bedoing表示對(duì)正在進(jìn)行的動(dòng)作的推測(cè)may/might+have

5、done表示對(duì)過(guò)去的推測(cè)Atpresent,theremaybesomeproblems.TheymighthavelotsofworktodonowbutImnotsure.ThismightbedonebyTom.Letsspeedup.Theymaybewaitingforus.表tk祝愿，用于倒裝句。May+主語(yǔ)+動(dòng)詞原形。Mayyousucceed!Mayheliveto100years!Mayyouhaveagoodlife!Itstoolate.Youmightaswellnotgo.Must表示說(shuō)話(huà)人主觀看法及強(qiáng)烈勸告“一定要必須”同haveto,只用于現(xiàn)在或?qū)?lái)，但是件環(huán)境迫

6、使必須，可用于各種時(shí)態(tài)。mustnt表示禁止，用以告訴別人不要做什么。don都是不必沒(méi)有必要用以回答must提問(wèn)的疑問(wèn)句。Youmusthaveapassportifyouwanttogoaboard.Youcangooutwithyourfriendbutyoumustcomebackbefore11atnight.IcantseeclearlysoIhavetowearglasses.MustIdoitnow?Yes,youmust.No,youneednt/donthaveto.表示推測(cè)，通常用于肯定句中，“一定”，很有把握，語(yǔ)氣最強(qiáng)烈。其否定形式為canMust+V原形表示對(duì)現(xiàn)在的狀態(tài)

7、特征推測(cè)Must+bedoing表示對(duì)正在進(jìn)行的動(dòng)作的推測(cè)Must+havedone表示對(duì)過(guò)去的推測(cè)Hemustbeill.Icanseeitfromhisface.Somethingmustbeburning.Icansmellit.Someonemusthaveenteredthisroomyesterday,formybookshavebeenmoved.表示偏要、固執(zhí)Hemustcomeandaskherquestionswhenshewasbusy.AsIwasabouttostarttowork,thetelephonemustphone.Need表示“需要”或“必須”，作為情態(tài)動(dòng)

8、詞時(shí)沒(méi)有人稱(chēng)和數(shù)的變化，多用于疑問(wèn)句和否定句中。must/haveto/oughtto/should.Youneedntexplain.NeedItakemoney?Yes,youmust./No,youneednt.作為實(shí)義動(dòng)詞時(shí)有人稱(chēng)和數(shù)的變化，后面要跟帶to的不定式。IneedtogotoBeijingthisSundaytoattendabookfair.haveto表示客觀條haveto禾口needntt/couldnt肯定句中用DoIneedtoleavemytelephonenumberandaddress?neednthavedone表示本沒(méi)有必要做某事。Ineednthave

9、boughtsomuchwineonlythreepeoplecame.Dare表示敢”，作為情態(tài)動(dòng)詞時(shí)沒(méi)有人稱(chēng)和數(shù)的變化，多用于疑問(wèn)句和否定句中。過(guò)去式為dared.HowdareyousayImnotfair”?Idarentstayathomealoneatnight.Youwillbepunishedifyoudarebreaktherule.作為實(shí)義動(dòng)詞時(shí)有人稱(chēng)和數(shù)的變化，后面要跟帶to的不定式。Thisstudentdoesntdaretoraisequestionsinclass.Doyoudaretodriveacaronsuchacrowedstreet?Idaretoswi

10、mintheriver.Shall用于第一、三人稱(chēng)疑問(wèn)句中表示征求意見(jiàn)或請(qǐng)求。Shallweputoffthesportsmeetuntilnextmonth?Henryiswaitingoutside.Shallhecomeinnow?用于二、三人稱(chēng)陳述句中表示說(shuō)話(huà)人的命令、警告、威脅、決心或許諾等感情色彩。Youshallgetananswertomorrow.Ifyoudosomethingwrong,youshallbepunished.Nothingshallstopme.Should作為shall的過(guò)去式用于第一、三人稱(chēng)疑問(wèn)句中表示征求意見(jiàn)或請(qǐng)求。Mr.Liaskedifhesho

11、uldgethispermittomorrow.表示義務(wù)職責(zé)或是給別人提出建議應(yīng)該。相當(dāng)于oughtto，但沒(méi)有oughtto語(yǔ)氣強(qiáng)烈。oughtto否定形式為oughtnotto或oughtntto,其一般疑問(wèn)形式要將ought放在主語(yǔ)前。IthinktodayschiIdrenshouldlearntorespecttheirelders.YououghttoapologizetoJoan.表示說(shuō)話(huà)人的感情色彩，如驚奇、憤怒、失望等。“竟然”Imsurprisedtheyshouldrefuseourinvitation.表示很大的可能性，“應(yīng)該”。Theyshouldarrivenow.

12、shouldhavedone本應(yīng)該做某事Youshouldhaveinvitedmetoyourwedding,butyouforgot.Will/Would表示請(qǐng)求，would語(yǔ)氣更加委婉。Willyoucomethisway,please?Wouldyouopenthewindow,please?表tK意志、愿望、決心。Iwontdothatagain.HesaidhewouldfightagainstAIDS.usedto,usedto的否定和疑問(wèn)形式tusetobesocareless.will表示習(xí)慣性動(dòng)作“總是”“慣于”；would表示過(guò)去經(jīng)常習(xí)慣做同都有兩種，分別借助于did和usedoFishwilldieoutofwater.Theoldmanisstrange.Hewillsitforhourswithoutsayinganything.Youwillregretifyoulosesuchagoodchanee.Afterdinner,hewouldsitaroundGrandpa,listeningtohisstories.Heusedtobecareless