八年級（上）英語教學課件外研版NSEUnit3LanguageinuseHelp八年級英語上（WY）教學課件Module12一、祈使句

祈使句表達說話人對對方的叮囑、勸告、希望、禁止、建議、請求或命令等。祈使句一般以動詞原形開頭，無時態(tài)和數(shù)的變化。常見的句型如下：1.動詞原形構(gòu)成的祈使句此類祈使句暗含的主語是you，但通常省略。否定句往往由donot（don't）或never開頭。祈使句的句首或句末有時加please，還可以加上稱呼語，用逗號與句子主體隔開。例如：Haveaniceday!

祝你度過美好的一天！Don'twasteyourtime!

別浪費時間了！Neverbelateagain!

再也不要遲到了！Comethisway,please.

請走這邊。Pleasebequiet,boys!

男孩們，請安靜！Makesurehe'swarm.

確保他不受涼。Don'tusethelift.

不要使用電梯。2.let's構(gòu)成的祈使句這類祈使句往往用于提出建議。例如：

Let'sspendthisweekendinthecountryside.

這周咱們到鄉(xiāng)下度周末吧。

Let'stakeataxi,shallwe?

我們坐出租車好嗎？3.無動詞祈使句在請求、命令和口號中，常用無動詞祈使句，它實際上是省略了動詞，從而使語句更簡潔有力。例如：

Justaminute,please!

請稍等！

Thisway,please!

請這邊走！二、情態(tài)動詞

must/can/could

表示推測

我們學習過情態(tài)動詞can和could表示“能夠，可以”等意義的用法。can和could還可以表示對現(xiàn)在或?qū)淼耐茰y，意為“會,可能”，但can表示推測時，往往用于否定句和疑問句。用于疑問句時，can比could表示的“可能性”要大；用于否定句時，cannot（can't）表示“不可能”。例如：

Youcan'tbeserious!

你不是認真的吧！could則可用于肯定句、否定句和疑問句。在以下例句中，can和could均表示可能：

Hecouldbeinpain.

他可能很疼。

Thatcouldbeharmful!

那可能有害！

Can/Couldthisbetrue?

這有可能是真的嗎?

情態(tài)動詞must也可以表示猜測，意思為“一定，準是”，通常只用于肯定句。如課文中的例子：

Betty,youmustknow!

貝蒂，你肯定知道！

請仔細對比下列一組句子：

Whosentthepresent?Canitbeyourbrother?

是誰送來的禮物啊？會是你哥哥嗎？（詢問可能性）Itmustbeyourbrother.Isawhiminyourroomjustnow.

肯定是你哥哥，我剛才看見他在你的房間里。（語氣強烈，表示非常肯定）

Itcan'tbemybrother.HeisstillinFrance.

不可能是我哥哥，他還在法國呢。（表示不可能）1.Completethesentenceswithcould,mustormustn’t.1Itisdangerous.You_____keepout!2Thesestairsarenotsafe.You______usethem.mustmustn’t3Therocksarefallingdown.You______gethit.4Theriveristoodeep.You_______swiminit.5Betty_____knowwhattodobecauseshedidsomebasicmedicaltraining.couldmustn’tmust2.Underlinethecorrectowrdstocompletethefirstaidinstructions.1Get/Donotgetmedicalhelpimmediately.2Ask/Donotaskthewherethepainis.3Lift/Donotliftthenbecauseyoumaydropthem.4Keep/Donotkeepthemwarm.√√√√3.Completetheposteraboutearthquakeswiththecorrectformofthewordsandexpressionsinthebox.

donotusehideunderkeepleavestayawayWhenthereisanearthquake...1_________fromthewindows.2__________atable.3__________thelift.4______thebuildingquicklywhenthegroundstopsshaking.5_____calm.StayawayHideunderDonotuseLeaveKeep4.Completetheconversationwiththewordsandexpressionsinthebox.

chanceCoverinpainintroublemedicalTony:Damingistraininghardforthebigmatch.Lingling:Yes,theteamhasagood(1)______thisyear.Tony:Ohno,Daming’s(2)_________.He'sdown!Lingling:Itlookslikehe's(3)_______.chanceintroubleinpainTony:Daming,whathappened?Daming:It'smyleg.Lingling:(4)______himwithmycoat.Tony:Butdon'tmovehim.Let'swaitforsomeonewith(5)_______training.Lingling:OK.Covermedical5.Completethenewsreportwiththecorrectformofthewordsinthebox.clearinsidepowerrocktroublewarnInformationiscominginthatcouldbe(1)

becauseofheavyraininthenorth.Thegovernmentis(2)

peopleaboutfalling(3)

.Someroadshavealotofrocksonthem,butpeoplearetryingto(4)

themquickly.Insomeplacesthereisno(5)

.Andpeoplemuststay(6)

tokeepawayfromfallingrocks.atroublewarningrocksclearpowerinside1.Thereareproblemseverywherebecauseofrain.()2.Thegovernmentiswarningpeopleaboutanearthquake.()3.Someroadsinthemountainshavealotofrocksonthem.()4.Peoplearetryingtocleartherocksofftheroads.()5.Thereisnoproblemwithpower.()××√√×Nowreadthereportagainandcheck(√)thecorrectsentences.7Readthepassageandchoosethecorrectanswer.1.What’sthebesttitleforthispassage?a)2004Asiantsunami.b)Agirlsavestouristsfromtsunami.c)Underwaterearthquakes.2.WhatdidTillynotice?a)Watercomingtothebeach.b)Peoplewatchingthewater.c)Bubblesinthewater.3.WhatdoesherteacherthinkofTilly?a)She’slucky.b)Shedoesn’tdosillythings.c)She’sacleverstudent.AroudtheworldEarthquakeareverycommoninJapan.Manycancausealotofdamage.Butnowtherearenewwaysofconstructingbuildingstomakethemsaferandstrongerduringearthquakes.TheYokohamaLandmarkTowerisoneofthetallestbuildingsinJapan.Itisheavyandstrong.Itsitsonrollers.Thismeanstheearthcanriseandfallbeneathtebuildingwithoutshakeingit.Moduletask:Makingaposteraboutpreventingaccidentsatschool8Mak