Unit 10 語法課件 2022-2023學(xué)年人教版英語八年級上冊

IF引導(dǎo)的條件狀語從句

if?Doyouknowthemeaningof......如果WhatcanyouFIND?it

willbreak.If

I

dropaglass,i

willgetwet.If

I

standinarain,I

willmiss

classes.If

I

come

toschoollate,if從句主句定義：if意為“如果”它引導(dǎo)的條件狀語從句表示“在…條件下，某事才能發(fā)生”，在復(fù)合句中充當(dāng)狀語。If引導(dǎo)的條件狀語從句位置：Ifyougototheparty,you'llhaveagreattime.You'llhaveagreattimeifyougototheparty.從句可放在主句之前或之后，但是放在主句之前須有逗號隔開If引導(dǎo)的條件狀語從句Ifyougototheparty,you'llhaveagreattime.Iftheyhavethepartytoday,halftheclasswon'tcome.Ifweaskpeopletobringfood,they'lljustbringpotatochipsandchocolate.Wewillhaveatripifitissunnytomorrow.想一想：哪個是主句？哪個是從句？If引導(dǎo)的條件狀語從句You'llhaveagreattime

,（主句）,ifyougototheparty(從句).Iftheyhavethepartytoday(從句）,halftheclasswon'tcome（主句）.Ifweaskpeopletobringfood(從句）,they'lljustbringpotatochipsandchocolate（主句）.Wewillhaveatrip（主句）ifitissunnytomorrow（從句）.If引導(dǎo)的條件狀語從句具體用法如果主句是一般將來時，從句則用一般現(xiàn)在時。（簡稱：主將從現(xiàn)）注意事項(xiàng)：將來時態(tài)需注意主句一般將來時用“willdo”的形式,不使用begoingtoIfit________(rain)tomorrow,Iwillstayathome.Ifit________(notrain)tomorrow,Iwillgooutforawalk.I_________(go)withyouifyoudon'twanttogoalone.You____________(be)happyifyougototheparty.rainsdoesn’trainwillgowillbeIf引導(dǎo)的條件狀語從句2.如果主句含有must,may,can等情態(tài)動詞，從句也要用一般現(xiàn)在時。（簡稱：主情從現(xiàn)）

Ifyoudrivetoofast,youmayhaveanaccident.Ifyouwanttopasstheexam,you__________________(study)hard.You____________(stop)ifthetrafficlightisred.You____________(leave)ifyoufinishyourhomework.must/shouldstudymuststopcanleaveIf引導(dǎo)的條件狀語從句3.如果主句是祈使句，從句同樣要用一般現(xiàn)在時。（簡稱：主祈從現(xiàn)）

Don’tgoand_______(play)footballifyoudon’tfinishyourhomework.Please________(call)meifhecomesnextSunday.Ifyouneedanyhelp,please_______(let)meknow.Ifyouwanttorecord,_________(press)theredlight.playcallletpress1、if從句：一般現(xiàn)在時主句：一般將來時

【主將從現(xiàn)】2、if從句：一般現(xiàn)在時主句：祈使句3、if從句：一般現(xiàn)在時主句：含can,may,must等情態(tài)動詞句子時態(tài)：If

在賓語從句中翻譯為“是否”If

在條件狀語從句中翻譯為“如果”I’llgotoseeyouifIamfreenextweek.

Iwanttoknowifheisateacher.whether1.if在句中的含義不同注意：

if引導(dǎo)的條件狀語從句與if引導(dǎo)的賓語從句的區(qū)別2.if在從句中的位置不同If引導(dǎo)的賓語從句放在主句之后；if引導(dǎo)的狀語從句可放在主句之前,也可放在主句之后用”，“隔開=Ifitdoesn’train,Iwillgoouttomorrow.Iwillgoouttomorrowifitdoesn’train.Idon’tknowifthetrainhasarrived.1.Canyoutellmeifshecancometothemeeting?2.Shewillnotgothereifitisrainytomorrow.3.Ican’tguessifshewillbeangry.4.Ifwehelpeachother,webothwillgetgoodresults.

判斷：if引導(dǎo)的條件狀語從句與if引導(dǎo)的賓語從句賓條件賓條件3.時態(tài)要求上有區(qū)別If

引導(dǎo)條件狀語從句的時態(tài)為一般現(xiàn)在時記住“主將從現(xiàn)”

1.Iwantedtoknowifthere

asportsmeetingnextmonth.doesn’trainwouldbe2.Ifit

,we’llholdit.If引導(dǎo)的賓語從句的時態(tài)由主句及本身時態(tài)決定1.if在句中的含義不同2.if在從句中的位置不同3.時態(tài)要求上有區(qū)別明白嗎

if引導(dǎo)的條件狀語從句與if引導(dǎo)的賓語從句的區(qū)別

if的反義詞：

if...not...=unless,“如果不，除非”

Iwon’tgothereunlessIhearfromyou.(同義句)Iwon’tgothere_____I_____hearfromyou.ifdon’t

Iwon’tgotothepartyifIamnotinvited.(同義句)Iwon’tgototheparty___________Iaminvited.unlessExercises

Hewillhelpmewithmymathsifhe____free.AwasBwillbeCwouldbeDisIdon’tknow_____hewillcometomorrow.____hecomes,I’lltellyou.Aif;WhetherBwhether;WhetherCif;ThatDif;If3.Pleasetellhermytelephonenumberifshe_____(want)toknow.wantsDD8.---Wouldyoupleasetellme____next?---Thinkitover.You’llfindagoodway.AwhentodoBhowtodoCwhattodoDwheretodo9.Idon’tknowifmyuncle_____.Ifhe___,Iwillbeveryhappy.Acomes;willcomeBwillcome;willcomeCcomes;comesDwillcome;comes10.EitheryouorI_____goingtoShanghai.Onlyonepersonmaygothere.AareBwereCamDwas

CDC()11.Ifit______sunnytomorrow,I____boating.

A.isgoB.willbe,go C.is,willgoD.willbe,willgo

()12.--whatwillyoudoifit______tomorrow,

--I’llstayathomeandwatchTV.

A.rainB.rainsC.willrainD.israining

CB()13.

Ifhe______,I______himthetime. A.comes,tellB.willcome,willtell C.comes,willtellD.willcome,tell()14.Ifit______,it______cold. A.snows,willbeB.snows,is C.willsnow,willbeD.willsnow,is()15.Ifyou______astoneintowater,it______. A.put,sinksB.put,willsink C.willput,sinksD.willput,willsinkCBA1.I’msureifhe_____(go)totheparty,he________(have)agreattime.2.Iftherain_______(stop)tonight,wewillgotothecinema.3.I’llbuyacomputerifI______(have)enoughmoney.4.You_________(notget)nervousifyou_____(do)enoughexercise.6.Iwanttoknowifhe_________(come)nextweek,ifhe_______(come),I__________(t