情态动词用法小结

情态动词用法小结

一、情态动词的基本用法•can could表示能力,意为“能够，会”如

1.I cantpromise anything,but Illdo whatI can.表示许可，意为“可以”如

2.You canuse thecar,if youwant.表示推测，常用于疑问句或否定句中在疑问句中意为“可能，也许”；在否定

3.句中，意为不可能”如cant couldntTheumbrella isneither yoursnor mine.Whose couldit beYoucant arriveat theairport ontime-it isnine oclocknow.•may might表示征求同意或允许，意为“可以”如

1.May Isit downYoumay comein ifyou wish.表示推测，意为“可能,也许”,比的语气更弱如

2.might mayWhynot turnto Mr.Smith forhelp Hemay knowthe answer.Mr.Wang mightget herein time,but I cant besure.•need意为“需要”可用于否定句、疑问句和肯定句中如You needntfinish thatwork today.Need Ihelp youpack yourluggage与•must have to都意为“必须”，但侧重说话人主观上的看法，即主观上的必要，而

1.must havet侧重客观的需要如I mustgo tothe bankto getsome money.I have to passan examinationbefore Ican startwork.有人称、数、时态的变化，而只有一种形式变为否定句

2.have tomust haveto或疑问句时，要借助于助动词如doI hadto lookafter mysister yesterday.Did theyhavetowork atsuch anearly ageto makea living回答引起的一般疑问句时，肯定回答用否定回答用或

3.must must,needrft dorft have如too一Must Ifinish thetask withinthis week—Yes,you must.No,you neednt.No,you donthaveto.还可以表示与说话人的愿望相反，意为“偏要，非要如

4.mustJohn,look atthe time.Must youplay thepiano atsuch alate hour表示比较有把握的推测，意为“一定，必定”，只用于肯定句中如

5.mustYou mustbe hungryafter yourlong walk.与•shall will would在疑问句中用于征求对方意见，主要用于第一人称如

1.ShanShall Ibring youa cupof coffee用于第

二、三人称时，表示说话人的意愿，可表示命令、威胁、许诺等如

2.shall（表命令）John shallgo first,whether hewants toor not.（表威月办）If youdont behaveyourself,you shallbe punished.俵许诺）You shallhear everythingas soonas youarrive.和表示征求意见或提出请求和均可用于第二人称的疑问

3.will wouldwill would句中，此时并不表示过去，而表示委婉语气如wouldWill Wouldyou pleasetell mehow toget tothe railwaystation和表示习惯和倾向性表示现在的习惯，表示过去的习惯，

4.will wouldwillwould有时表示经常发生的令人不耐烦的事如Every morningmy fatherwill havea walkalong thisriver.When shewas a child,Ann wouldoften asksome strangequestions.Thaf sjust likeher-she wouldlose herbag inthe bus!与•should ought to与都可以表示职责和义务，意为“应该，应当“，两者常可互换,

1.should ought但的语气更强一些如ought toYoushould helpyour motherwith the housework.You reallyought toapologize.与也可表示猜测，意为“可能，应该会”如

2.should ought toI havebought threeboxes.That oughtto should be enough.还可以表示说话人不能理解某事，感到意外或难以置信，意为“居然，竟

3.should然”如Icanhardly believethat thereshouldbeso manypoor peoplein sucha richcountry.的否定式是或者疑问式是将提前如:

4.oughttoought not to oughtntto,oughtYou oughtntto leaveso youngachildalone inthehouse,ought youOughtI toask theteacher foradvice

二、情态动词动词形式+have+・ed在英语中，表示对过去某种情况或已发生的动作进行推测，常用“情态动词+动词形式”表示说话人的语气或推测的把握程度不同，使用的情态动词have+-ed也不同

4.needn5thavedone意为“本不需要做.......却做了“如:I neednthave writtento himbecause hephoned meshortly afterwards.