1、现在完成时一、现在完成时构成构成：现在完成时由助动词have + 过去分词构成，助动词have 有人称和数的变化。第三人称单数用has，其余用have.现在完成时的否定式直接在助动词后面加上not、疑问式是把助动词提到主语之前。以study 为例，其否定式、疑问式和简单回答形式如下：否定式疑问式I have not (havent) studied.Have I studied?You have not (havent) studied.Have you studied?He has not (hasnt) studied.Has he studied?否定疑问式简单回答（肯定/否定）Have
2、 I not (Havent I) studied?Yes, you have. No, you havent.Have you not (Havent you) studied?Yes, I have. No, I havent.Has he not (Hasnt he) studied?Yes, he has. No, he hasnt.二、现在完成时用法1、现在完成时通常表示在说话之前已经完成的动作或存在的状态。说话人强调的是该动作或状态对现在的结果或影响。My daughter has just gone out. 我女儿刚出去。Im sure weve met before. 我肯定
3、我们以前见过面。She has arrived. 她到了。2、表示持续到现在的动作或状态，往往和包括现在在内的表示一段时间的状语连用，如recently, already, just, lately, for, since,yet等。如：I havent heard from her these days. 这些日子我没有收到她的信。We havent seen you recently. 最近我们没有见到你。They have been away for two years. 他们离开已经两年了。She has been with us since Monday.for+时段since+过去
4、一个时间点（译为：自从以来）since+时段+agosince+从句（过去时）It is+时段+since+从句（过去时）Mary has been illfor three days.I have lived heresince 1998.注意：since和for的区别since后接时间点，如1993，last term, yesterday, the time I got therefor后接一段时间，表示“长达多久”，如ten years, a while, two days等。3、表示短暂意义的动词如arrive, leave, borrow, buy, begin, start, d
5、ie等，在完成时当中不能和表示一段时间的状语连用，因为它们表示的动作不可能持续。因此，不能说：He has come here for 2 weeks. The old man has died for 4 months. They have left only for 5 minutes. 4、has gone (to),has been (to), has been (in)的区别Have/Has gone(to) :去了(现在不在说话现场，可能在路上和已经到)Where is your father?He has gone to Shanghai.Have/Has been (to) :
6、去过（已不在去过的地方）My father has been to Shanghai.Have/has been in：呆了多久（还在所呆的地方）My father has been in Shanghaifor two months. /since two months ago.5、现在完成时不能和表示过去的时间状语连用，如yesterday, last year, in 1976, two days ago, just now, when I came in，但可以和already, yet, sometimes, always, often, before, lately, recent
7、ly, once, twice, ever, never等连用。不能与when连用。现在完成时往往同表示不确定的过去时间状语连用例如：She has already come. 她已经来了。I havent read it yet. 我还没读过这个。I have met him before. 我从前曾见过他。Ma Hong has always been a good student. 马红一直是个好学生。I have often seen him in the street. 我经常在街上看见他。They have never been to Yanan. 他们从未去过延安。I haven
8、t seen him lately. 我近来没看到他。三、现在完成时的标志1、现在完成时的含义之一是过去完成的动作对现在仍有影响,用以下四大标志词可以表达这种含义:*以already, just和yet为标志Hehas already gother help.他已得到她的帮助。Hehas just seenthe film.他刚刚看过这场电影。Hehasnt comebackyet.他还没有回来。*以ever和never为标志This is the best film Ihave ever seen.这是我曾经看过的最好的一部电影。Hehas never beento Beijing.他从没有
9、到过北京。*以动作发生的次数为标志He says hehas been tothe USAthree times. 他说他已经去过美国三次了。*以so far（到目前为止）为标+beforeHehas gotto Beijingso far.到目前为止他已到了北京。She has passed the exam so far.到目前为止她已经通过了考试。2.过去已经开始的动作一直延续到现在, 甚至有可能继续延续下去,我们可以从动作“延续”的特性和“时间”点段的区分入手,进一步学习现在完成时。for+时段since+过去一个时间点（过去从句）为标志四、瞬间动词buy, die, join, co
10、me，go ,leave, join 不能直接与for since连用。要改变动词buy-haveborrow -keepcome/arrive/reach/get to-be ingo out-be outleave -be awaybegin-be onfinish-be overopen-be openclose -be closeddie-be dead1、have代替buyMy brother has had(不能用has bought) this bike for almost four years.2、用keep或have代替borrowI have kept(不能用have b
11、orrowed) the book for quite a few days.3、用be替代becomeHow long has your sister been a teacher?4、用have a cold代替catch a coldTom has had a cold since the day before yesterday.5、用wear代替put on6、用“be形容词”代终止性动词bemarried代marry beill代fall (get) illbedead代die beasleep代fall (get) asleepbeawake代wake/wake up begon
12、e代lose,die,sell,leavebeopen代open be closed代close/shutbemissing(gone,lost)代lose7、用“be副词”代终止性动词beon代start begin “beup”代get up “beback(to)”代return to, come back to, go back to “be here (there)”代come(arrive, reach, get) here或go (arrive, reach, get) there8、用“be介词短语”代终止性动词1.“be in/at +地点”代替go to /come to2
13、.用be in the army代替join the army3.“be in/at +地点”代替move to常用瞬间动词变延续性动词表：1. have arrived at/in sw. got to/reached sw. come/gone/moved to sw.have been in sw./at相应的介词2. have come/gone back/returned have been back3. have come/gone out have been out4. have become have been5. have closed / opened have been
14、close/open6. have got up have been up；7. have died have been dead；8. have left sw. have been away from sw.9. have fallen asleep/got to sleep have been asleep；10. have finished/ended/completed have been over；11. have married have been married；12. have started/begun to do sth. have done sth.；13. have
15、begun have been on14. have borrowed/bought have kept/had15. have lost havent had16. have put on have worn17. have caught /get a cold have had a cold；18. have got to know have known19. have/has gone to have been in20. have joined/have taken part in the league/the Party/the armyhave been a member of/ have been in/have been the Partys member/the league member/the soldier
