need的用法：

need的用法：•need的用法：•1.实义动词(有人称和数的变化）•sth.•.①sb.+needtodosth..sth.todosth.eg.Ineedsomehelp.eg.Ineedtosleep.eg.needtimetodosth.Heneedstimetodohomework.•②sth.+needdoing•(表被动含义)•=sth.+needtobedone•eg.Thehouseneedscleaning.•=Thehouseneedstobecleaned•2.情态动词（没有人称和数的变化）•need用于句首构成一般疑问句或needn’t才为情态动词。注意：need作为情态动词时，后面必须接动词原形。•常用句式：•Needsb.dosth?•sb.needn’tdosth.•eg.NeedIgo?•Heneedn’tgohomebybus.•Exercises:•()1.Heneeds___timewithhischild.•A.spendsB.spending•C.tospendD.spend•()2.Tom___somemoneytobuybooks.•A.needtoborrowB.needstoborrow•C.needsborrowD.needsborrowing•()3.You___theretoday.•A.needn’tgoingB.needn’ttogo•Cdon’tneedtogoD.don’tneedgoing•()4.Theflowersneeds___.•A.watersB.towater•C.wateringD.wateredCBCC•“didn’tneedtodo”和“needn’thavedone”两种结构的用法和区别：•A.didn’tneedtodosth.表示“没有必要做而实际上也没有做某事”的意思。如：•Ididn’tneedtocleanthewindowsbecausemyyoungersisterdidit.•因为我妹妹已经把窗户擦了，因此我不需要擦了。（实际我没擦）•B.needn’thavedonesth.表示“本来不必做某事而实际上却做了”的意思。如：•Youneedn’thavecometomyofficeyourself.Youcouldhavegivenmearinginstead.•你本来不必亲自来我办公室的，只要给我个电话就可以了。（实际上你已经来了）•想一想如下结构的含义：•(1)musthavedonesth•(2)may/mighthavedonesth•(3)can’t/couldn’thavedonesth•(4)can/couldhavedonesth•(5)should/shouldn’thavedonesth•(6)oughttohavedonesth情态动词+havedone1)musthavedone对过去已经发生的事的肯定推测.(只用于肯定句)Hemusthavegonetobed,forthelightwasout.2)can/couldhavedone对过去行为的怀疑和不肯定的推测.(常用于否定句和疑问句)在否定句意为“不可能,不会是”Mickcan’t/couldn’thavefoundhiscar,forhecametoworkbybusthismorning.(不可能/不会找到车)有时含有责备或遗憾的意思.Youcouldhavedoneitbetter.Youcouldhavecomeearlier.你本可以把这件事做得更好.你本可以来的更早.3)may/mighthavedone表示推测,可能性更小,主要用于肯定句.译为:“或许”Hemay/mighthavegonetothelibrary.他或许已经去图书馆了.might+havedone有时含有委婉的责备或庆幸等感情.这时不能用mayYoumighthavetoldmeearlier.你本可以早点把消息告诉我的.4)shouldhavedone表示本应该做但却未做,含有“后悔,遗憾,责备,批评”之意.Youshouldhavebeenmorecareful.你本应该更细心些.Youshouldn’thavetoldhimaboutit.你本不该告诉他这事.5)needn’thavedone表示“本来用不着,本不必”之意.Youneedn’thaveaskedhim.(Butyouaskedhim.)Youneedn’thavecome.Ihavefinishedthework.1.Ididn’tseeherinthemeetingroomthismorning.She________（can)havespokenatthemeeting.2.Therewasplentyoftime.She_________(need)havehurried.3.Iwasveryconcernedaboutyou.You_______________(notleave)withoutaword.4.Yourmotherisveryangry.Shemust__________________(know)thetruth.5.Ican’tfindmywalletnow.Imight___________(leave)itinthecar.couldn’tneedn’tshouldn’tleavehaveknownhaveleft