1八年级下册语法知识重点1.If引导的条件状语从句（1）当主句和从句所表示的是原理、客观事实、规则时，主句是一般现在时（包括祈使句和含有情态动词can，may，must等），从句也用一般现在时。e.g.1.Youmustseethedoctorifyouareill.如果你生病了，你就必须去看医生。（含情态动词）2.Ifyoustickapinintoaballoon,itbursts.如果你用针刺气球，它就会爆炸。（原理）3.Becarefulifyoucrosstheroad.如果你过马路，请小心。（祈使句）（2）在if引导的条件状语从句中，如果从句谈论的时一个有可能发生的事实及其产生的相关的结果，主句用一般将来时态，从句用一般现在时态。e.g.1.Ifitrainstomorrow,wewillnotgotothezoo.2.Ifyougotobedearlier,youwon’tfeeltiredinthemorning.2.后带ing和do的动词seeSeesbdosth看到某人经常做某事或做某事的全过程Seesbdoingsth看到某人正在做某事noticeNoticesbdosth注意到某人经常做某事或做某事的全过程Noticesbdoingsth注意到某人正在做某事watchWatchsbdosth观察到某人经常做某事或做某事的全过程Watchsbdoingsth观察到某人正在做某事hearHearsbdosth听到某人经常做某事或做某事的全过程Hearsbdoingsth听到某人正在做某事listentoListentosbdosth听见某人经常做某事或做某事的全过程Listentosbdoingsth听见某人正在做某事3.情态动词Should一、作为情态动词，通常用来表示现在或将来的责任或义务，表示“应该，应当”。e.g.Crimeshouldbepunished.犯罪应受惩罚。二、作为情态动词，可以用来表示有较大可能实现的猜测、推论，表示“可能，该(=willprobably)”。e.g.Theheadmastershouldarrivesoon.校长可能很快就到了。Theyshouldbehomebynow，Ithink.我想现在他们总该到家了吧。2Exercise:情态动词练习题1.Jean___havekepthispromise.Iwonderwhyhechangedhisidea.A.mustB.shouldC.needD.would2.---CouldIuseyourbike?----Yes,surelyyou___.A.mightB.willC.canD.should3.It’snearlyeighto’clock.Bruce___behereatanymomentA.mustB.needC.shouldD.can4.Tommy,you___playwiththeknife,you___gethurt.A.won’t;can’tB.mustn’t;mayC.shouldn’t;mustD.can’t;shouldn’t5.Whenhewasthere,he___gotothatcoffeeshopatthecornerafterworkeveryday.A.wouldB.shouldC.hadbetterD.might6.---Whencanyougetthefilmdeveloped?Ineedittomorrowmorning.----It___bereadyby8：00.A.canB.shouldC.mightD.need7.---Willyoustayforanotherhour?-----Sorry,___.Oneofmybestfriendsiscomingtoseeme.A.Imustn’tB.Ican’tC.Ineedn’tD.Iwon’t8.Jasonshouldn’t___meyoursecret,buthemeantnoharm.A.havetoldB.tellC.betellingD.havingtold9.---Areyoucomingfordinner?----I’mnotquitesure.I___gotomyuncle’sinstead.A.mustB.wouldC.shouldD.might10.---Don’tforgettovisitmewhenyoucometoBeijing.------___.A.Idon’tB.Iwon’tC.Ican’tD.Ihaven’t11.Heought___havedonesoeventhoughpossible.A.nottoB.tonotC.notD.never12.Jane___havecometotheparty,butshe___notfindtheexacttime.A.could;couldB.might;couldC.should;couldD.should;would313.Somanymistakesinyourhomework!You___morecareful.A.maybeB.hadtoC.wouldbeD.shouldhavebeen14.Herbrother___beathomenow,becausehewasseenplayingbasketballinthestadiumjustnow.A.mustn’tB.needn’tC.can’tD.shouldn’t15.---Ican’tunderstandwhyourbossislate.------He___theearlybus.A.couldmissB.mayhavemissedC.canhavemissedD.mightmiss答案：1---5BCCBA6---10BBADB11---15AADCB4.动词+介词/动词+副词动词+介词：构成的词组相当于一个及物动词，宾语总是在介词后面。e.g.Idon’tmuchcareforthetelevision.我不是很喜欢电视。动词+副词：构成的词组可作及物动词，也可作不及物动词。作及物动词时，宾语的位置有两种情况：宾语如果是名词，则可放在副词后面，也可放在动词与副词之间；而如果宾主是代词，只能放在动词后面，即动词和副词之间。作不及物动词时，后不带任何名词或代词作宾语。e.g.Somethingunexpe...
