1、Ive finished my homework now.现在我已经做完作业了。（说明可以交作业或做别的了）2）表示过去动作的结果，现在仍残留着。一般不用时间状语。I have lost my pen.我把笔丢了。（说明过去某时丢的，现在我还没找到这支笔）She has become a teacher.她已经当了老师。（说明她现在仍是老师）II.“未完成”用法。表示动作或状态从过去某时开始，持续到现在，可能继续下去，也可能刚刚结束。常和表示一段时间的状语连用。如today，this week（month），lately，recently，these days，in the past few
2、days，during the last two weeks，since，since yesterday，since 2 days ago，since 1991，for a long time，for a month，so far，up to now，till（until） now等。He has lived here for 30 years.他住在这儿三十年了。（现在还住在这儿）Theyve known each other since childhood.他们从小彼此相识。（现在还在往来）How long have you studied English？你学英语多久了？（现在仍在学）I
3、II.经验性用法:表示从过去开始到目前为止这段时间中反复发生的动作或多次出现的状态。常与频度副词如often,always,every week,twice等连用。I have been to the Summer Palace twice.我曾经去过颐和园两次。He has always said so.他总是这么说.三.现在完成时的时间状语I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,last Sunday,in1990,three years ago等。但是，在强调动作产生的后果和影响时，可以和一些表示不确定的时间状语连用。a. 用副词already和y
4、et。already一般用于肯定句中，yet一般用于否定句和疑问句中。We have already finished our homework.我们已完成作业了。They havent finished their homework yet.他们还没有完成作业。b. 用ever和never.多用于否定或疑问句中，表示“曾经”或“从未“等。 -Have you ever been to the Great Wall?你曾经去过长城吗?-I have never been to the Great Wall.我从未去过长城。c. 用表示到说话为止的过去时间状语，如just,before,up t
5、onow,the past few years等。例如：I have seen her before,but I can not remember where.我以前见过她，但记不起在哪里见过。He has been there three times the last few days.近几天他去过那里三次了。d. 用包括“现在”在内的时间状语，如now,today,this morning（month,year,term）等。-Have you met him today?-No,I havent.今天你见过他吗？我没有。How many times have you been there
6、 this year?今年你去过那里多少次？II短暂性动词不能和表一段时间的时间状语连用。come, go, arrive, reach, hear, close, leave, begin, start, lose, buy, fall, join, die, get up等。但如果要保留表一段时间的时间状语，必须将动词改为延续性动词。现归纳总结一下由非延续性动词到延续性动词的转换 fall asleep （ill） be asleep （ill）get to know know begin,（start） be onopen be open buy haveget up be up die
7、 be deadgo out be out come be inclosebe closed arrivebe herejoinbe in, be a +名词 finish（ end ）be overleave, move be away,borrow keepgo to schoolbe a studentcatch（a cold） have（a cold）begin to studystudycome backbe backput onwear 或be onHe has been a soldier for three years.他参军三年了。His father has been de
8、ad for two years.他父亲去世二年了。The film has been on for 5 minutes.电影已开始五分钟了。We have studied English for three years. 我们（开始）学英语已三年了。四.几点注意事项I. have been（to）与have gone（ to）的区别：have been（to）表示“去过某地（现在已经回来了）”，可用于各人称；have gone（to）表示“去某地了（说话时某人不在当地）”，常用于第三人称，前者可与once ,never,several times等连用，后者则不能。They have bee
9、n to Beijing twice.他们去过北京两次。He has gone to Beijing . 他去北京了。II.不可延续性动词现在完成时的否定式，已变成一种可以延续的状态，因此可以和表示一段时间的状语连用。I havent left here since 1997.自从1997年以来，我一直没有离开过这儿。（错）I have received his letter for a month.（对）I havent received his letter for almost a month.练习一.用since和for填空1._two years 2._two years ago3.
10、_last month 4._ 19995._yesterday 6._ 4 oclock7 4 hours 8._an hour ago9._we were children 10._ lunch time11._ she left here12. He has lived in Nanjing _ the year before last.13. Ive known him _ we were children.14. Our teacher has studied Japanese _ three years.15. She has been away from the city _ a
11、bout ten years.16. Its about ten years _ she left the city.二.单项选择。1、Both his parents look sad . Maybe they _whats happened to him . A. knew B. have known C. must know D.will know2、He has _ been to Shanghai , has he ?A. already B.never C.ever D.still3、Have you met Mr Li _？A. just B. ago C.before D. a
12、 moment ago4、The famous writer _ one new book in the past two year . A. is writing B.was writing C.wrote D.has written5、Our country _ a lot so far . Yes . I hope it will be even _ . A.has changed ; well B.changed ; good C.has changed ; better D.changed ; better 6、Zhao Lan _already _in this school fo
13、r two years . A. was ; studying B. will ; study C. has ; studied D. are ; studying 7、We _ Xiao Li since she was a little girl . A. know B. had known C. have known D. knew8、Harry Potter is a very nice film .I_ it twice . A.will see B.have seen C.saw D.see9、These farmers have been to the United States . Really ? When _ there ? A. will they go B. did they go C. do they go D. have they gone 10、_ you _ your homework yet ? Yes . I _ it a moment ago . A.Did
