现在完成时讲解9450

一、定义：现在完成时（Presentperfect）过去发生并且已经完成的动作对现在造成影响或后果，过去某一时间开始并一直持续到现在并且有可能还会持续的动作或状态。1：表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止，可能仍然在进行。常带有for和since等表示一段时间的状语。fortwofor+一段时间Jimhaslivedherefor2months.monthssincelastyearsince+过去点时LucyhasbeeninBeijingsincesince3yearsago间3yearsago.since1990sincehesince+过去时态HehasbeeninChinasincehecamehere.camehere句子<注>因为此时是强调持续一段时间并有可能继续持续下去，所以如果是肯定句的话动词必须要是延续性的，否定句不需要2:表示动作发生在过去某个不确定的时间，但对现在留下了某种影响和结果。常被just、already、yet、uptonow、thepastfewyears、sofar等副词修饰。-Haveyouhadlunchyet?-Yes,Ihave.I'vejusthadit.你（已经）吃午饭了吗？我刚刚吃过。（现在我不饿了）<注>此处强调过去的动作对现在造成的影响。二、构成have\has+过去分词肯定have/hasdone否定haven’t/hasn’tdone-1-疑问have/has提前三、过去分词变化规则规则动词的变法和过去式相同，即直去双改。直：直接加-ed如played,missed,matched,wished,stayed,picked,e后加-ed.如saved,hoped,wasted,lived,waved,moved去：去双：以重读闭音节结尾的词双写后面是辅音字母后加-ed如：stopped,fitted.stepped,stirred改：以辅音字母+y为结尾的词变y为i后加-ed如：fried,tidied,carried四、标志词的位置①already已经肯定句中或句尾e.g.:Ihavealreadyfoundmypen.=Ihavefoundmypenalready.②yet已经否定句和疑问e.g.：Ihavenotfinishedtheworkyet.Haveyouboughtacomputeryet?句句尾③ever曾经e.g.：Haveyoueverseenpandas?句中④never从不句中e.g.：IhaveneverbeentoBeijing.⑤just刚刚句中-2-e.g.：Ihavejustdonemywork.⑥before以前句尾e.g.：Ihaveneverbeentherebefore.特别注意：现在完成时属于现在时范围，故不能和过去的时间状语连用。如：yesterday,lastSunday,in1990,threeyearsago等对for或since引导的时间状语提问，必须用howlong,不能用when.IhavebeeninFuzhoufortwomonths.→HowlonghaveyoubeeninFuzhou?LindahasstudiedChinesesince5yearsago.→HowlonghasLindastudiedChinese?像come,arrive,buy等终止性动词不能与表示“一段时间如：Hehasboughtthebookfor3years.（错）因buy这个一次性动词不能和一段时间for3years连用”的状语连用。,改正的办法有五种：(去掉一段时间for3years)(改为一子的意思①Hehasboughtthebook..②Heboughtthebook3yearsago般过去时，使句不变)③It’s3yearssinceheboughtthebook.=3yearshaspassedsinceheboughtthebook.（改为固定句型Itis---since---）-3-④Hehasnotboughtthebookfor3years.（改为否定句）⑤Hehashadthebookfor3years.（用延续性动词have代替buy）还有其他一次性动词也是这种情况，可参照前面的五种办法改正，前四种改法都一样，第五种改法各不相同，举例如下：①come/arrive/getto/reach→behereIhavecomeherefor3years.（错）改为：Ihavebeenherefor3years.②leave/go→beawayHehasleftfor3hours.（错）改为：Hehasbeenawayfor3hours.③begin/start→beonThefilmhasbegunfor3minutes.（错）改为：Thefilmhasbeenonfor3minutes.④open→beopen/close→beclosedTheshophasopenedfor3years.(错)改为：Theshophasbeenopenfor3years.⑤die→bedeadHisfatherhasdiedfor3years.(错)改为：Hisfatherhasbeendeadfor3years.⑥finish/end→beoverHehasfinishedtheworkfor3days.(错)改为：Theworkhasbeenoverfor3days⑦joinIhavejoinedthearmyfor3years.（错）Ihavebeeninthearmyfor3years.或Ihavebeenasoldierfor3years.⑧buy/catch→have改为：Ihaveboughtthebikefor3years.（错）改为：Ihavehadthebikefor3years.Hehascaughtacoldfor3days.（错）改为：Hehashadacoldfor3days.⑨borrow→keep-4-Ihaveborrowedthebookfor3years.（错）改为：Ihavekeptthebookfor3years.延续性动词和终止性动词①延续性动词：表示的动作是能延续的动作，这种动作可以延续下去或产生持久的影响。e.g.：learn\work\stand\lie\know\walk\keep\have\wait\watch\sing\read\sleep\live②终止性动词：也叫非延续性动词，瞬间动词，一次性动词。表示的动作不能延续，即动作发生后立即结束，产生某种结果。在有了某种结果后，动作就不能再继续下去。常用的瞬间动词有：come，go,die,becomebegin,borrow,join,buyarrive,finish,return,leave,open,closebegin(start)→beonleave→beawayfromgo-beoffborrow→keepcome-beherejoin→bein或beamemberof…die→bedeadbuy-havearrive→behereReturn(comeback)-bebackputon→wear或beonfallill(sick,asleep)→beill(sick,asleep)getup→beupgoout→beout-5-finish→beoverclose→beclosedbuy→haveopen→beopengotoschool→beastudentcatch(acold)→have(acold)不要忘记把转换过的动词变为过去分词have