情態(tài)動詞講解

情態(tài)動詞一、情態(tài)動詞的含義1.Theboycouldspeakthreelanguageswhenhewas12.2.MayIhaveyourname?3.Shallwebeginnow?4.Youmustobeytheschoolrules.1.含義：表示說話人的情緒、態(tài)度或語氣的動詞2.特點：情態(tài)動詞不能單獨(dú)作謂語，需要與另外一個動詞一起作謂語eg.Hecanplaybasketballwell.3.否定式在情態(tài)動詞后直接加noteg.maynotcan和could的用法關(guān)于“can"的句子1.表“能力”Somedogscansmelloutdrugs(毒品).一些狗能夠嗅出毒品。2.表“許可”CanIuseyouriphone?3.表示“推測”，用于否定句中表示“不可能”Youcan'tbetired.Youhaveonlybeenworkingforanhour.你不可能累，你僅僅工作了一個小時。4.表示客觀的可能性，意為"有時可能會"Everyonecanmakemistakesinhislife.5.表示“驚訝”“懷疑”態(tài)度Howcanyoubesocareless?could1.表示can的過去式Hecanspeakthreelanguages.Hecouldspeakthreelanguageswhenhewasthreeyearsold.2.表示現(xiàn)在的“能力和許可”，語氣比can委婉CouldＩcometoseeyoutomorrow?Yes,youcan.(答語只能用can)/No,I'mafraidnot.can的習(xí)慣用法1.can'thelpdoingsth忍不住；不禁我情不自禁的笑了起來。Ican'thelplaughing.2.can't(help)butdo只好做某事;不得不Ican'thelpbutwaitforher.3.can't.....too....再....也不為過Youcan'tbetoocarefulwhendriving.開車時你再小心也不為過。havedone結(jié)構(gòu)1.can/couldhavedone或can't/couldn'thavedone表示對過去事情的推測Youcouldn'thaveseenhimlastnight.Isawhimoffattheairport.2.couldhavedone表示對過去的虛擬，意為本能夠做某事Youcouldhavedonebetter,butyoudidn'ttryyourbest.May和might的用法1.表示征求意見或請求許可MayＩuseyourcar?Yes,youcan.might更加委婉2.表“可能”Theroadmay/mightbelocked.a.might表示過去的可能b.might表示現(xiàn)在的可能，比may的可能性小3.may位于句首表示祝愿Mayyoubehappy!Mayyousucceed!4.習(xí)慣用法May/mightaswelldosth(最好，不妨）我最好還是去。Imightaswellgo.5.havedone結(jié)構(gòu)a.may/mighthavedone表示對過去事情的推測Nobodyansweredthedoor.Theymighthavefallenasleep.b.mighthavedonesth表虛擬，意為“本來可以”Youmighthavegivenhimmorehelp.must的用法1.表“必須”Plantsmusthavewaterinordertolive.植物必須有水才能活。must主觀haveto客觀2.表“推測”，意為“準(zhǔn)是，一定”a.must+v對現(xiàn)在情況的推測Hemustbedad.他準(zhǔn)是瘋了。b.must+be+ving對將來或現(xiàn)在進(jìn)行時的推測Itmustberainingtomorrow.明天一定胡下雨。c.musthavedonesth對過去事情的推測Shedidn'tcometoschool.Shemusthavebeenill.3.must用于疑問句中，表示責(zé)備或抱怨，譯為“偏要或非得”Mustwehandinourhomeworktoday?Yes,youmust.4.mustn't意為“禁止”Carsmustn'tbeparkedhere.will的用法1.will用于第二人稱的疑問句表示征求意見2.will/would表示個人意愿,意為“要；愿”3.will/would表示“習(xí)慣性，經(jīng)常性”，意為“總是，老是”4.will/would表示事物的功能或傾向性，意為“能，行”Iwilldomybesttohelpyou.Whenhewasthere,hewouldgotothatcoffeeshopafterworkeveryday.Thedoorwon'topen.Wouldyouacceptthisinvitation?征求意見時would較will委婉客氣個人意愿某種習(xí)慣，經(jīng)常性事物的功能征求意見5.wouldhavedone表示對過去的虛擬，意為本來可以Johndidn'tworkhardathislesson,otherwisehewouldhavepasssedtheexam.shall的用法1、用于第一、第三人稱的疑問句，表示征求意見Shallwebeginourclass?Shallhecometoseeyou?2、用于第二、第三人稱的陳述句，表示命令、威脅、警告或承諾Sheshallstudy,orsheshallleavethecollege.HeshallhavethebookwhenIfinishreading.警告承諾3.shall表示法律條文和規(guī)章制度中的要求意為（按照規(guī)定）必須，應(yīng)該P(yáng)ersonsunder18shan'tbeemployedinwork.should的用法1、表示責(zé)任、義務(wù)、勸告、建議，意為"應(yīng)該"Studntsshouldrespectteachers.Theyshouldbereadyby12:00.2.在肯定句中表示推測，意為“按理應(yīng)該”Itshouldbeafinedaytomorrow.It's4o'clock.TheyshouldbeinNewYorknow.(可能性比must?。?.表示驚訝、贊嘆或不滿情緒，意為“竟然會”Ican'timaginethatsuchawell-dressedmanshouldbesorude.4.should/shouldn'thavedonesth，對過去的虛擬意為“本應(yīng)該、本不應(yīng)該Theyshouldhavefinishedtheirhomework.need的用法1.need在肯定句中多用于實義動詞Heneedstofinishitthisevening.2.做情態(tài)動詞多用于否定句、疑問句、條件句Ineedn'tuseaclocktowakemeupbecauseatsixo'clockeachmorningthetrain