Unit1语法专项课件-目的不定式沪教版英语八年级下册

教学课件沪外教英语八年级下册Unit1语法专项—Infinitiveofpurpose（目的不定式）

全解精讲+分层练习

学习目标1.理解目的不定式的定义及核心表达含义2.掌握目的不定式的3种基本结构及使用场景3.熟记目的不定式的同义替换形式及转换规则4.掌握否定结构的正确表达，规避常见错误5.攻克核心考点，能完成各类题型的解题应用

语法定义Infinitiveofpurpose（目的不定式）核心形式：to+动词原形核心含义：表示“为了……”，表动作发生的目的核心用法：可回答由Why引导的特殊疑问句简单例：Istudyhardtogetgoodgrades.（为了取得好成绩）基本结构1句中表目的结构公式：主语+谓语+（宾语）+to+动词原形使用场景：目的状语放句中，无需强调目的例句1：Igototheparktotakephotos.译：我去公园，为了拍照。例句2：ShestudiesEnglishtocommunicatewithforeigners.基本结构2句首强调目的结构公式：To+动词原形+,+主句使用场景：需要突出、强调动作的目的注意：句首To后接动词原形，后必须加逗号例句1：Tokeepfit,sheswimseveryweekend.译：为了保持健康，她每周游泳。基本结构3回答Why问句结构公式：直接用To+动词原形使用场景：对Why引导的特殊疑问句进行简答问答示例：—Whydoyougetupearly?—Tocatchtheearlytrain.译：——你为什么早起？——为了赶早班火车。小练习辨结构填内容根据结构补全句子，体会不同用法1.我学画画为了培养兴趣。Ilearndrawing______develophobbies.2._____________(save)money,sheseldombuyssnacks.3.—Whydoyoupracticerunning?—_____________(win)thematch.toTosaveTowin同义替换1todo=inordertodo=soastodo核心规则：三者后均只接动词原形，可直接互换适用场景：句中表目的，不可用于句首（soastodo）原句：Iworkhardtomakemoremoney.替换1：Iworkhardinordertomakemoremoney.替换2：Iworkhardsoastomakemoremoney.同义替换2todo=sothat+完整句子核心区别：todo接动词原形；sothat后接主谓完整的句子常配情态动词：sothat后常加can/could/will/would原句：Igetupearlytocatchthebus.替换句：IgetupearlysothatIcancatchthebus.译：我早起，为了能赶上公交车。同义替换对比表形式后接内容适用位置todo动词原形句中/句首inordertodo动词原形句中/句首soastodo动词原形仅句中sothat+句子完整主谓句句中/句首小练习同义句转换将下列句子用不同形式改写，体会替换规则1.Hereadsbookstoknowmoreknowledge.（用inorderto改写）2.Shepracticesdancingtowinthecompetition.（用sothat改写）Hereadsbooksinordertoknowmoreknowledge.Shepracticesdancingsothatshecanwinthecompetition.否定结构核心规则正确形式1：inordernotto+动词原形正确形式2：soasnotto+动词原形规则：not放在to之前，后接动词原形，无其他变形否定结构例句解析例句1：Hewalksquietlyinordernottowakethebaby.译：他轻步走，为了不吵醒宝宝。例句2：Wehurryupsoasnottomissthefilm.译：我们赶紧走，为了不错过电影。

核心考点1to后接词规则考点核心：to后永远接动词原形禁止形式：不能接ing/第三人称单数s/过去式ed例句正解：Shewentouttobuyapen.（过去时，to后仍用buy）例句错误：Shewentouttoboughtapen.（×）核心考点2时态不影响to后形式考点核心：主句无论用过去/现在/将来时to后面的动词始终用原形现在时：Istudytogetgoodgrades.过去时：Istudiedtogetgoodgrades.将来时：Iwillstudytogetgoodgrades.考点易错题辨析判断下列句子正错，并改错1.Hestudieshardtogetsgoodmarks.

2.Theywillgotheretovisittheirteacher.3.Shecameheretoseeingherfriend.

×gets→get√×seeing→see拓展目的不定式与for的区别易混点：todo和for都可表“为了”，用法不同1.todo后接动作（动词原形）：Igotheretoplay.2.for后接对象/事物（名词/代词）：Igothereforfun.口诀：to加动，for加名，表目的时要分清。拓展特殊情况省略to的情况注意：本单元目的不定式必须加to特殊拓展：使役动词/感官动词后省to（非目的）例：Letmehelpyou.（let后省to）Seehimrun.（see后省to）区分：Icomeheretohelpyou.（目的不定式，必加to）语法小结核心框架（一）1.核心形式：to+动词原形（表“为了……”）2.三种结构：句中、句首（加逗号）、答Why问句3.同义替换：inorderto/soasto/sothat+句子4.否定结构：inordernotto/soasnottodo语法小结核心框架（二）5.核心考点：to后永远接动词原形，不受时态影响6.易混辨析：todo接动词，for接名词/代词7.常见错误：不可直接用nottodo表目的否定8.特殊提醒：本单元目的不定式必须加to，不省略综合练习题型1单项选择

1.Shegoestothebookstore______somestorybooks.A.buyB.tobuyC.buyingD.buys2.______improvehismath,hetakesextraclasses.A.ToB.ForC.WithD.At3.—Whydoyoucarryabag?—______putmybooksinit.A.ForB.ToC.AtD.On4.Theyexerciseeveryday______healthy.A.keepB.keepingC.tokeepD.kept5.Hesavedmoney______travelaroundtheworld.A.toB.forC.atD.withBABCA6.Ilistentotheradio______mylisteningskills.A.improveB.toimproveC.improvingD.improved7.______finishtheworkontime,weworktogether.A.ToB.ForC.OnD.In8.Weneed______something______helpthepoorkids.A.do;toB.todo;toC.doing;forD.do;for9.Sheleftearly______missthelastbus.A.inordertonotB.nottoC.soasnottoD.tonot10.Heopensthewindow______somefreshair.A.togetB.getC.gettingD.gotBABCA综合练习题型2用所给词正确形式填空1.Mymothercooksbreakfast__________(feed)useverymorning.2.__________(learn)Chinesewell,helivesinChinanow.3.Theygotothegym__________(keep)theirbodiesstrong.4.—Whydoyoupracticesinging?—__________(become)asinger.5.Heusesacomputer__________(search)forinformation.tofeedTolearntokeepTobecometosearch综合练习题型2用所给词正确形式填空6.Wetalkquietly_________________(notdisturb)thestudentsinthelibrary.7.ShejoinstheEnglishclub________________(make)foreignfriends.8.________________(pass)theexam,hestudieslateeverynight.9.Iwritedownthewords________________(remember)themeasily.10.Theyplanttrees________________(make)thecitymorebeautiful.inordernottodisturb/soasnottodisturbtomakeTopasstoremembertomake综合练习题型3句型转换1.Hepracticesswimmingeveryday.Hewantstowinthegame.（合并成一句）Hepracticesswimmingeveryday____________thegame.2.Igotothecinema.Iwanttowatchanewmovie.（合并）Igotothecinema____________anewmovie.3.TomasterEnglishisnecessary.（改写为It句型）It’snecessary____________English.4.Shedidmoreexercises.Shewantedtoimprovehermath.（合并）Shedidmoreexercises____________hermath.towintowatchtomastertoimprove综合练习题型4根据中文完成句子1.我每天练钢琴是为了提高技巧。Ipracticethepianoeveryday____________myskills.2.为了学好书法，他每天坚持练习。____________calligraphywell,hekeepspracticingeveryday.3.他们种树是为了美化环境。Theyplanttrees____________theenvironment.toimproveTolearntobeautify4.我带伞是为了不被雨淋。Itakeanumbrella_______________________________caughtintherain.5.他努力工作是为了给家人更好的生活。Heworkshard____________abetterlifeforhisfamily.6.为了赶上上课，他跑着去学校。____________theclass,herunstoschool.inordernottobeto