八年级英语下册unit8 grammar.ppt

1、Unit8HaveyoureadTreasureIslandyet?,SectionAGrammarFocus,GrammarFocus,现在完成时态presentperfect,现在完成时：表示过去发生或已经完成的某一动作对现在造成的影响或结果，或从过去开始一直延续到现在的动作或保存的状态。,结构：主语+have/has+动词的过去分词,一般疑问句：have/has?Yes,Ihave.No,Ihavent.Yes,shehas.No,shehasnt.,1.现在完成时动词构成have/has+v过去分词,助动词,否定,haventhasnt,疑问,Haveyou?Hashe?,常与下列时间

2、状语连用：just,already,yet,ever,never,before,severaltimes,现在完成时,1.过去发生的动作对现在造成的影响或结果。和already，never,ever,just,before,yet等状语连用。,2.过去已经开始，持续到现在的动作或状态，常与for或since引起的一段时间状语连用。,动词构成：have/has+v过去分词,havebreakfast,Ihavejusthadmybreakfast.,(现在我不饿),Imnothungrynow,movedherein2004,Istilllivehere,Ihavelivedhereforthr

3、eeyears.,Ihavelivedheresince2004/threeyearsago.,now,past,2.现在完成时动词可以表示开始于过去持续到现在(也许还会继续进行下去)的动作或状态。1)IhavestudiedEnglishsincelastyear.我从去年开始学习英语。2)ShehaslivedinBeijingforfiveyears.她住在北京已经五年了。注意:come,go,leave,arrive,buy,lose,receive,join,die,bury和marry等动词所表示的动作是一时的,不能延续的,故不能与for,since等开头的表示一段时间的状语连用。

4、不过,这些词用于否定句则可以与表示持续的时间状语连用，即动作的不发生是可以持续的。,不能说:*HehascometoBeijingfortwoyears.*Hehasboughtthatbookforthreeweeks.*HehasjoinedtheArmyforoneandahalfyears.*Hisgrandmahasdiedforninemonths.*Ihavereceivedhisletterforamonth.可以说:HehasbeeninBeijingfortwoyears.Hehashadthatbookforthreeweeks.Hehasbeeninthearmyfor

5、oneandahalfyears.Hisgrandmahasbeendeadforninemonths.Ihaventreceivedhisletterforalmostamonth.,或者说：ItistwoyearssincehecametoBeijing.Itisthreeweekssinceheboughtthatbook.ItisoneandahalfyearssincehejoinedtheArmy.Itisninemonthssincehisgrandmadied.,3.现在完成时把过去的动作和现在的结果联系起来，一般过去时只限于表示过去的动作本身,与现在的结果无关。现在完成时与一

6、般过去时在意义上的区别举例如下：Ihavecleanedmyroom.(Myroomiscleannow.)我已经打扫过我的房间了。Icleanedmyroomlastweek.(Ididitinthepast.)我上周打扫了我的房间。FatherhasgonetoAmoy.(HewenttoAmoyandheisnotherenow.)爸爸已经去厦门了。Theyhaveboughtadictionary.(Theyboughtadictionaryandtheyhaveitnow.)他们买了一本字典。,注意:现在完成时不能和明确指出时间的状语(如:yesterday,last,year,in

7、1976,twodaysago,justnow,whenshecamein等)连用，但可以和不明确指出时间的状语(如:already,yet,ever,never,sometimes,always,often,before,once,twice,recently,lately等)连用；也可以和表示包括现在在内的时间状语(如：today,thismorning,thisweek,thisyear等)连用。,(1).for+表示一段时间的短语(2).since+表示过去时间点的词语(3).since+表示过去时间的时间状语从句,eg.Ihavebeenateacher_ayear.Hehasbee

8、natthisschool_1992.Wehavelearned1,000Englishwords_wecametothisschool.,for,since,since,现在完成时句中常见的时间状语A.表示从过去一直持续到现在,不能是具体的过去时间。,ever,just,already,yet,e.g.Haveyou_beentoJapan?Ihave_finishedmyhomework.Ihavefinishedmyhomework_.Ihaventfinishedmyhomework_.,B.just,already,yet,before/ever,never有此类副词时,常强调动作完

9、成,不强调动作的持续.,already“已经”;yet“仍然,还”这两个副词常常用于完成时态,其中already常用于肯定句,yet常用于否定句和疑问句中。如:Jimhasalreadyfinishedhiswork.Jim已经把他的工作做完了。Motherhasntcomehomeyet.妈妈还没回来。HaventyoureadTheCalloftheWildyet?你还没读过野性的呼唤吗？,Shehasalreadyfinishedherwork.她已经把工作做完了。Ihaventreadthestoryyet.我还没读过这个故事。Haveyoumethimbefore?你从前曾见过他吗？

10、Lilyhasalwaysbeenagoodstudent.Lily一直是个好学生。比较：Ihaveseenhimthismorning.我上午看见他了。(说话时在上午)Isawhimthismorning.今天上午我遇见了他。(说话时可能是下午或者晚上)Ithasbeencoldthiswinter.今天冬天一直很冷。(说话时仍是冬天),4.现在完成进行时和现在完成时都可以表示“从过去开始一直持续到现在”这一概念,有时两者可以互相代用,但前者多用于口语。在含义上如着重表示动作的结果时,多用现在完成时;如着重表示动作一直在进行,即动作的延续性时,则多用现在完成进行时。一般不能用于进行时的动词也

11、不能用于现在完成时行时。,现在完成时：表示过去发生或已经完成的某一动作对现在造成的影响或结果，或从过去开始一直延续到现在的动作或保存的状态，强调的是现在的情况，不能和表示过去的时间状语连用（如：in1990，lastSunday等）。,一般过去时：一般过去时只表示过去的动作或状态，和现在不发生关系（即动作或状态在现在已经结束），它可以和表示过去的时间状语连用。,现在完成时与一般过去时的区别：,have/has+V过去分词,一、过去式和过去分词的变化相同规则变化：1.一般在动词词尾直接加ed。如：pickpickedpicked;wishwishedwished;staystayedstayed

12、2.以不发音的e结尾的动词后面加d。如：likelikedliked;hopehopedhoped;phonephonedphoned,3.以“辅音字母+y”结尾的动词，变y为i，再加-ed。如：studystudiedstudied;hurryhurriedhurried;replyrepliedreplied4.词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stopstoppedstopped;clapclappedclapped,不规则变化：5.以不变应万变。如：letletlet;putputput;readreadread6.若中间有双写e，则去掉一个e，单词

13、末尾再加t。如：feelfeltfelt;keepkeptkept;sleepsleptslept,7.结尾的字母d变t。如：lendlentlent;buildbuiltbuilt;sendsentsent8.变为以-ought或-aught结尾。如：buyboughtbought;bringbroughtbrought;catchcaughtcaught;teachtaughttaught,Ihavewaitedforhimformanytimes.我等他等了好几次了。Ihavebeenwaitingforhimforanhour.我等他等了一小时。Hehasdrunksixcupsofc

14、offee.他喝了六杯咖啡。Hehasbeendrinkingcoffee.他一直在喝咖啡。,改写句子,1.Myfathercamebackfromthebookshopjustnow.Myfather_just_thebookshop.2.HebegantolearnChinesein2001.He_Chinesesince2001.3.Thefilmbegantwominutesago.Thefilm_sincetwominutesago.4.Hehashadthemotorbikefortwoyears.Itstwoyears_he_themotorbike.He_themotorbik

15、etwoyears_.Twoyears_sincehe_themotorbike.,has,returned,from,has,learned,hasbeenon,since,bought,bought,ago,haspassed,bought,1.A:Wouldyoulikesomethingtodrink?B:No,thanks._(just/drinksometea)2.A:Iheardyoulostyourkey._?(find)B:No,notyet.3.A:DoyouknowwhenTomisleaving?B:_.(already/leave),4a.Usethewordsinb

16、racketstocompletetheconversations.,Ivejustdrunksometea,Haveyoufoundit,Hehasalreadyleft,A:When_?(leave)B:Thismorning.4.A:Isyoursistergoingtothemovieswithustonight?B:No._.(already/seethefilm)5.A:Whatdoyourparentsthinkaboutourplan?B:I_.(not/tellthem/yet),didheleave,Shehasalreadyseenthefilm,havenottoldt

17、hemyet,Sally_(love)reading.Inthemorning,shereadsthenewspaperandintheeveningshereadsbooks.She_already_(read)morethan100differentbooks!Herfavoritekindofbooksissciencefiction.Sheisinterestedinscienceandtechnologyandlovestoimagine,4b.Fillintheblankswiththecorrectformsofthewordsinbrackets.,loves,hasread,whattheworld_(be)likein50years.She_(finish)readingabookaboutrobotslastweekand_(write)abookreportaboutitnextweekforherFrenchclass.Everytimesheisinthelibrary,Sallylooksatthemanybooksshe_(notread)yetands