A．表示过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。现在完成时跨在两个时间之上，一是过去，一是现在。它的动作发生在过去，但对现在有影响（或结果），而这种影响（或结果）却往往是说话人的兴趣所在，所以常常后面不用时间状语。现在完成时所表的动作离说话人的说话时刻可近可远，表近距离的。eg.Thecarhasarrived.车子来了。（结果：车子已在门口）Someonehasbrokenthewindow.有人把窗户打破了。（结果：窗户仍破着）现在完成时句子通常有recently，lately，since，for，inthepastfewmonths/years等词做时间状语。肯定形式：have/has+done否定形式：have/has+not+done一般疑问句：have或has放于句首。B．现在完成时的用法1）现在完成时所表示的动作在说话之前已完成，而对现在有影响。所以常常后面不用时间状语。现在完成时所表的动作离说话人的说话时刻可近可远。eg.HehasgonetoLondon.HehasbeentoLondon.2）现在完成时所表示的动作开始于过去，持续到现在，也许还会持续下去。常用for和since表示一段时间的状语或sofar，now，today，thisweek(month，year)等表示包括现在时间在内的状语。eg.HehasstudiedEnglishfor5years.HehasstudiedEnglishsince2001.NowIhavefinishedthework.注意：表示短暂时间动作的词，如:come，go，die，marry，buy等的完成时不能与for，since等表示一段时间的词连用。用来持续的动作或状态或表过去重复的动作，如live，study，be，wait等，常和since（自从）或for（经历）引导的词语连用。如：Ihavelivedhereformorethanthirtyyears.我已在此住了30多年。3）现在完成时还可用在时间和条件状语从句中，表示将来某时完成的动作。eg.I’llgotoyourhomewhenIhavefinishedmyhomework.Ifithasstoppedsnowinginthemorning，wewillgotothepark.现在完成时练习一、单项选择。1、Bothhisparentslooksad.Maybethey______what'shappenedtohim.A.knewB.haveknownC.mustknowD.willknow2、Hehas_______beentoShanghai,hashe?A.alreadyB.neverC.everD.still3、HaveyoumetMrLi______？A.justB.agoC.beforeD.amomentago4、Thefamouswriter_____onenewbookinthepasttwoyear.A.iswritingB.waswritingC.wroteD.haswritten5、—Ourcountry______alotsofar.—Yes.Ihopeitwillbeeven______.A.haschanged;wellB.changed;goodC.haschanged;betterD.changed;better6、ZhaoLan______already______inthisschoolfortwoyears.A.was;studyingB.will;studyC.has;studiedD.are;studying7、We______XiaoLisinceshewasalittlegirl.A.knowB.hadknownC.haveknownD.knew8、HarryPotterisaverynicefilm.I______ittwice.A.willseeB.haveseenC.sawD.see9、—ThesefarmershavebeentotheUnitedStates.—Really?When_____there?A.willtheygoB.didtheygoC.dotheygoD.havetheygone10、—______you___yourhomeworkyet?—Yes.I_____itamomentago.A.Did;do;finishedB.Have;done;finishedC.Have;done;havefinishedD.will;do;finish11、Hisfather______thePartysince1978.A.joinedB.hasjoinedC.wasinD.hasbeenin12、—Doyouknowhimwell?—Sure.We_________friendssincetenyearsago.A.wereB.havebeenC.havebecomeD.havemade13、—Howlonghaveyou____here?—Abouttwomonths.A.beenB.goneC.comeD.arrived14、Hurryup!Theplay__________fortenminutes.A.hasbegunB.hadbegunC.hasbeenonD.began15、It_____tenyearssinceheleftthearmy.A.isB.hasC.willD.was16、MissGreenisn'tintheoffice.she_______tothelibrary.A.hasgoneB.wentC.willgoD.hasbeen17、Myparents______Shandongfortenyears.A.havebeeninB.havebeentoC.havegonetoD.havebeen18、Thestudentshavecleanedtheclassroom,______?A.sotheyB.don’ttheyC.havetheyD.haven’tthey19、______hasMrWhitebeenamemberofGreenerChinasincehe______toChina?A.Howsoon,comesB.Howoften,gotC.Howlong,cameD.Howfar,arrived20、Hisuncle______formorethan9years.A.hascomehereB.hasstartedtoworkC.haslivedthereD...
