Unit3单元语法解析与训练课件人教版八年级英语下册

Unit3Couldyoupleasecleanyourroom?语法解析与训练一、情态动词could的用法1.礼貌请求（提出请求或征求许可）句型结构：

※Couldyou(please)+动词原形+其他？（委婉请求对方做某事）例如：Couldyoupleasetakeouttherubbish?

Couldyoupleasetakethedogforawalk?Couldyouplease(not)do...?※

CouldI+动词原形+其他？（征求对方允许）例如：CouldIuseyourphone?

CouldIgooutfordinnerwithmyfriends?CouldI/wedo...?

回答方式：肯定回答：Yes,youcan./Sure./Ofcourse

/Certainly./OK./Noproblem.等（需用can而非could）否定回答：Sorry./Certainlynot./I‘mafraidIcan’t./No,youcan‘t等.+说明理由例如：-Couldyouopenthewindows?你能打开窗户吗?-Sorry,butIhaveacold.抱歉-Couldyoupleasetakeouttherubbish?-OK-CouldIuseyourphone?–Sorry，itisbroken2.表示过去的能力情态动词could作为can的过去式时，表示过去的能力和可能性，其否定形式为couldnot，可缩写为couldn't.例如：Hecouldwritepoemswhenhewas10.Judycouldn'thaveenoughmoneytobuyacar.Hecouldswimwhenhewasfive.3.表示推测（可能性较低）推测现在或过去的可能性，语气比can更弱。例如：Hecouldbeathomenow.※与can的区分can用于直接请求或表示当前能力，could更委婉回答could的请求时需用can/can’t，不能用could。易错点提示：1.对提出请求或征询许可的句型做否定回答时，通常以sorry或I'msorry开头。例如：-CouldyouhelpmewithmyEnglishnow?-I'msorry,butIhaveafootballmatchtenminuteslater.2.如果问句中使用could，回答时要用can或can't，不能用could或couldn't。例如：-CouldIuseyourbike?-Sure,youcan.-Couldyoupassmethesalt?

—Yes,Ican.（正确）—

Yes,Icould.（错误）3.否定请求结构：Couldyoupleasenot+动词原形？例如：Couldyoupleasenotshout?【延伸知识】其他常见的表示委婉请求或征询许可的句型:(1)Will/Wouldyoupleasedo...?表示请你做……好吗?(2)Wouldyoumind(not)doing......?表示“你介意(不)做……吗?”(3)MayI……?表示“我可以……吗?”练习题

用can/could/can’t/couldn’t填空He______singanddance.Heisverytalented.2.—______youpleasehelpmewiththedishes?—Yes,I______.3.Hesaidhe______cometotheparty.Iwasdisappointed.4.—______sheswimattheageof6?—No,she______.答案：1.can2.Could;can3.couldn’t4.Could;couldn’t单项选择1.—CouldIborrowyourdictionary?—______.A.Yes,youcouldB.No,youcouldn’tC.Sure,hereyouareD.Never**答案：C**2.—Couldyoupleasenotopenthewindow?—______.A.Sorry,Iwon’tB.No,Icouldn’tC.Yes,pleaseD.Ofcourse**答案：A**3.—Wouldyoumindmysmokinghere?—_____.Can'tyouseethesignNosmoking?A.OfcoursenotB.NoC.NevermindD.You'dbetternot答案：1.C2.A3.D4.-Couldyourideabikewhenyouwere5yearsold?-___.ButIcouldsingsomesongs.A.No,Ican't.B.No,Icouldn't.C.Yes,Ican.D.Yes,Icould.5.-Paul,couldyouplease__theTV?Jimissleepingnow.-Sorry.I'lldoitrightnow.A.turnupB.turningupC.turndownD.turningdown6.Attheageoffive,Allen__tellsomefamousChinesestories.CouldB.MustC.needD.Might答案：4.B5.C6.A7.-Wouldyoumind___thewindow?It'sveryhot.-No,notatall.A.OpenB.toopenC.openingD.opens8.-Couldyoulendmethebookyouboughtlastweek?-___.A.Yes,hereyouareB.No,Ican'tlendC.It’snotinterestingD.Agoodidea9.---Couldyoupleasebuy___drinksandsnacks?---Sorry.Idon'thave_____money.A.some,anB.any,anyC.some,someD.any,some答案：7.C8.A9.A10.---Couldyouhelpmewiththemathproblem?_____.I'mtoobusynow.A.Yes,pleaseB.No,sureC.Yes,youcouldD.Sorry,Ican't11.-CouldIborrowyourcar?-___,Ineedit.I_gotoschool.A.Certainly;don'tB.Sorry;havetoC.Certainly;don'thavetoD.Sure;haveto12.-CouldIuseyourbike?-Yes,ofcourseyou__.A.CanB.couldC.mustD.will答案：10.D11.B12.A13.--Couldyoufinishthetaskintwodays?-__.Ihavesomethingelsetodothesedays.A.IcouldnotB.Yes,IthinksoC.I'mafraidsoD.I'mafraidnot14.---Lily,couldyouhelptofeedmycatwhileI'maway?___.A.No,Idon'tB.Yes,IwillC.No,Imustn'tD.Yes,Imust15.-CouldIborrowyourcamera?-_______,butpleasegiveitbackbySaturday.A.IamsorryB.OfcourseC.CertainlynotD.No,thanks答案：13.D14.B15.B16.-Couldyoupleasewashthefruit?-_A__.IcutmyfingerandI'mtryingnottogetitwet.A.No,Ican'tB.Yes,sureC.No,youcan'tD.Yes,youcan17.Here’ssomuchrubbish.Couldyouplease__D__?A.giveoutitB.giveitoutC.takeoutitD.takeitout18.Kim___B__playtheviolinfiveyearsago,butnowhecanplayitwell.mustn'tB.couldn'tC.needn'tD.shouldn't答案：16.A17.D18.B19.-Sir,couldyoupleaseputoutyourcigarette(香烟)?Thisisasmoke-free(无烟的)school.-_A.I'msorryaboutthis.B.Noproblem.C.Sure,I'dlovetoD.Nevermind.20.-CouldIborrowthebook?____,thatwouldbeOK.Ifinishedreadingityesterday.A.ThankyouB.I'msorryC.NevermindD.Ofcourse答案：19.A20.D本单元涉及到的其他语法项目（简单介绍）1.assoonas引导的时间状语从句assoonas表示一……就……，用于连接两个动作，强调后一个动作紧跟前一个动作发生。

它引导的是时间状语从句，需注意主句和从句的时态搭配。用法详解1）.时态规则：如果主句用一般将来时（willdo），则从句用一般现在时（do/does）表示将来的动作。

例如：

IwillcallyouassoonasIgethome.（我一到家就会给你打电话。）

-Shewillsendmethereportassoonasshefinishesit.（她一完成报告就会发给我。）2.）主句和从句动作的先后顺序

从句动作（由assoonas引导）先发生，主句动作随后立即发生。

例如：Assoonastherainstops,wewillgoout.（雨一停，我们就出去。）

Heturnedoffthelightassoonashelefttheroom.（他一离开房间就关了灯。）如果主句是过去时态，从句根据实际情况用过去的某种时态3）从句位置的灵活性assoonas从句可放在主句前或后，放在句首时需加逗号。

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例如：Assoonasthebellrings,theclassbegins.（铃声一响，课就要开始了。）

Theclassbeginsassoonasthebellrings.（课在铃声一响就开始。）易错点与注意事项时态一致性错误

错误：Iwilltellhimthenewsassoonashewillcomeback.

正确：Iwilltellhimthenewsassoonashecomesback.（他一回来，我就告诉他这个消息。）主句为祈使句的情况

句是祈使句时，从句仍用一般现在时。

例如：

Pleaseclosethewindowassoonasyouleave.（离开时请立刻关窗。）练习

用assoonas合并句子：

Ifinishmyhomework.Iwillplaybasketball.答案：IwillplaybasketballassoonasIfinishmyhomework.翻译句子：

妈妈一准备好晚餐，我们就吃饭。

答案：WewillhavedinnerassoonasMompreparesit.选择题1.Nextmonthwe'regoingsomewhereinterestingassoonastheholiday___A.willbeginB.hasbegunC.beginsD.isbeginning答案：C.2.-Iwanttoknowifhe___backtomorrow.-I'llcallyouassoonashe.A.willcome;willreturnB.willcome;returnsC.comes;willreturnD.comes;returns3.Assoonasyou___home,giveacalltoletmeknowyou___safely.A.get;havearrivedB.willget;havearrivedC.get;willarriveD.willget;arearriving答案：2.B3.A2.neither引导倒装句的结构与用法基本结构

Neither/Nor+be动词/助动词/情态动词+主语

用于表示前文提到的否定情况同样适用于后文的主语，意……也不。

例如：

LiLeican’tdance.NeithercanTom.（李雷不会跳舞，汤姆也不会。）

Shehasn’tseenthatfilm.NeitherhaveI.（她没看过那部电影，我也没看过。）2.使用条件

前句为否定句，且后句主语与前句不同。

助动词（如do、does、did等）、be动词（am/is/are/was/were）或情态动词（如can、must等）需与前句保持一致。

例如：

Tomdoesn’tlikebananas.Neitherdoeshiswife.（汤姆不喜欢香蕉，他妻子也不喜欢。）注意事项时态一致性：后句的动词形式需与前句时态一致。

例如：

前句用一般过去时（didn’t），后句也用did：

Hedidn’tsmoke.N