现在完成时讲解及练习.doc

现在完成时精讲练习1.概念：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。2.时间状语：recently, lately, sincefor,in the past few years, etc. 3.基本结构：have/has + done 4.否定形式：have/has + not +done. 5.一般疑问句：have或has提前对于初接触现在完成时的人来说，往往会产生一种茫然，因为它似乎与一般过去时相似。那就是，这两种时态描述的动作都始于过去。其实不然，现在完成时主要表示，发生在过去的动作延续到现在刚刚完成、或许还要延续；侧重于这个动作对现在带来的结果、产生的影响、积累的总和等等。而一般过去时则只不过是表示动作发生在过去的什么时候。弄清了这一区别，就很容易理解现在完成时了。它主要适用于下面的几种情况：1）表示截止现在业已完成的动作By now, I have collected all the data that I need .到现在为止，我已收集到了我所需的全部资料。She has read 150 pages today .她今天已看了150页。2）表示发生在过去而对现在产生影响、带来结果的动作Have you had your dinner? 你吃晚饭了吗？3）表示过去发生的动作持续到现在，并可能还要延续It has been five years since he joined the army .他参军五年了。1)一个句子应该用什么时态只能取决于它需要表达的意思，以及它所处的语言环境。例如：He speaks English .（一般现在时，说明动作发生的经常性。）He spoke English when he was in New Zealand .（一般过去时，说明动作发生的时间。）He is speaking English.（现在进行时，说明动作正在进行。）He has spoken English for three years since he came to the USA.（现在完成时，这里说明动作的总和。）He has been speaking English since he came to the USA. （现在完成进行时，强调动作的连续性。）2）在含有时间状语从句或条件状语从句的主从复合句中，如果主句的谓语动词是一般将来时，那么从句的谓语动词就只能用一般现在时来表示将来时；如果主句的谓语动词是过去将来时，那么从句的谓语动词就只能用一般过去时来表示过去将来时。例如：I will not play tennis if it rains tomorrow.I would not play tennis if it rained the next day.3) 有些动词表示无法持续的动作，它们一般不宜用于进行时态中。这类动词常见的有：be , believe , consist , find , forget , hate , have , hope , hear , know , like , love , notice , prefer , remember , see , seem , smell , suggest , taste , understand , want , wish , sit down , stand up 等等。Be动词若是用于进行时态，可表示暂时、短暂的情况或表现。例如：Tom is being a good boy today .汤姆今天很乖。He is being childish .他这样做是耍孩子气。You are not being modest .你这样说不太谦虚。4）关于现在完成时的时间状语问题A. 凡是完成时态都表示，不知道也不管动作发生的具体时间, 所以在使用现在完成时的句子里，不可以带有表示具体过去时间的状语，如：yesterday , last week ( month , year , etc. ) , two weeks ago , in 1999等；但常和有些副词连用，如： just , before , already , often , never , ever , notyet , always等等。B. 在以when提问的特殊疑问中不能用现在完成时。另外，ago不能用于现在完成时的句子里，因为它表示从现在算起的以前某个时间，属于表示具体过去时间的状语。但是可以用before 来表示以前的意义，因为它只表示以前，而不知什么时候的以前。C. 如果是不表示连续性的动词用于现在完成时的句子，不可以和以for表示的一段时间的状语连用。在这种情况下，应该用It has been ；since的句式来表达。如：He has joined the army for five years. （错误）It has been five years since he joined the army.（正确） 能与现在完成时连用词语很多，如副词just, already, yet, before, ever, recently 等，但下面是一些典型而且重要的例子：(1) since(自从)：不管用作介词、连词还是副词, 句子(主句)谓语通常都用现在完成时：I havent seen her since last week. 自上周以来我一直未见过她。Where have you been since I last saw? 自我上次见到你之后你到哪里去了?【注】有时可用其他时态的情况，但须注意： 对于某些表示状态的动词(如 seem 等)，或因语义等方面的原因，有时可能用一般现在时比较现在完成时更合适：It seems like years since we last met. 我们似乎几年未见面了。Since when does the $42 plus $5 service charge come to $48? 从什么什候开始42元加5元的服务费等于48元了? 若不是指从过去持续到现在，而是指从较远的过去持续到在一个较近的过去，则用过去完成时：Yesterday he told me that he hadnt eaten anything since Tuesday. 他昨天告诉我自星期二以来他一直未吃任何东西。(指从星期二至昨天未吃东西) 表示时间长度时，通常用一般现在时代替现在完成时：Its ten years since he left here. 他离开这儿已10年了。(2) so far(到目前为止)： So far there has been no bad news. 到现在为止还没有什么坏消息。We havent had any trouble so far. 到目前为止，我们还没有遇到任何麻烦。 (3) in for, during the past last years(在过去年中)：In the past two years Ive seen him little. 过去两年我很少见到他。I have been here (for) the last past month. 最近一个月里我都在这儿。【注】在一定的上下文里，若是以过去时间为起点，也可用过去完成时。(4) up to until now(到现在为止)：Up to now, the work has been easy. 到现在为止这工作还算容易。I have heard nothing from him up to now. 到现在为止我还没有听到他一点音信。(5) Its will be the first time that(第一次)：Its the first time Ive come here. 这是我第一次来这儿。延续性动词与非延续性动词之间的转换leave-beawayborrow-keepbuy-havedie-bedeadbegin/start-beonfinish-beoverfallill-beillgetup-beupcatchacold-haveacoldputonwearcome/become/go-beherefallasleep-beasleepgetto/arrive/reach-be(in)gettoknow-knowjoin-beamemberof.open-beopenclose-beclosed用相应的延续性动词替换短暂性动词，句中谓语动词用现在完成时，时间状语为“for时间段”或“since时间点”。如：HehasbeenintheGreenChinaforthreeyears.HehasbeenamemberoftheGreenChinaforthreeyears.他加入“绿色中国”已经三年了。Theoldmandied4yearsago.-Theoldmanhasbeendeadfor4years.HejoinedtheParty2yearsago.-HehasbeeninthePartyfor2years.Iboughtthebook5daysago.-Ihavehadthebookfor5days.表示时间段的短语有:for+一段时间(for2years),since+从句(sincehecamehere),since+时间点名词(sincelastyear,since5daysago),howlong;foralongtime等。V.现在完成时态与一般过去时态的区别1一般过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。Isawthisfilmyesterday.（强调动作发生的时间是yesterday。）Ihaveseenthisfilm.（强调对现在的影响，电影的内容已经知道了。）2一般过去时和表示过去的时间状语连用，如：ago,lastweek/.In2008,inthepast,justnow,thedaybeforeyesterday,yesterday.Then(那时),thatday,oneday,once(从前)现在完成时常和recently（近来），ever,never,twice,sofar（到目前为止）,since，for，inthepast/lastfewyears,already（肯定句）,yet（否定，疑问句）,just(刚刚),before（以前）连用。现在完成时不与表示过去的时间状语连用。现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如live,teach,learn,work,study,know.VI.比较since和forsince后接时间点，for后接时间段，试比较：Ihavelivedhereformorethantwentyyears.IhavelivedheresinceIwasborn.Myaunthasworkedinacompanysince1949.Ihavenotheardfrommyuncleforalongtime.VII.比较have/hasbeento、have/hasgoneto和havebeeninhave(has)beento.表示“曾去过某地，已经从那里回来了”，可以和ever、never、twice等连用。have(has)goneto表示“已经去了某地，在去那里的途中或到达那里还没有回来”。have(has)beenin表示“在某地呆多长时间”，常与表示一段时间的状语连用，如：since,for,howlong等HewenttoShanghailastweek上周他去了上海HehasbeentoShanghai.他(曾经)到/去过上海.(但他人现在肯定不是在上海而是回来了)HehasgonetoShanghai.他已经去上海了.(也许刚动身出发,也许已经到了,也许还在路上,反正他人不在这里)Mr.BrownhasbeeninShanghaiforthreedays.布朗先生来上海已经有三天了现在完成时练习一、单项选择1、Both his parents look sad .Maybe they _whats happened to him . knew . have known . must know .will know2、He has _ been to Shanghai , has he ?. already .never .ever . still3、Have you met Mr Li _？. just . ago .before . a moment ago4、The famous writer _ one new book in the past two year. is writing .was writing .wrote .has written 5、-Our country _ a lot so far .-Yes . I hope it will be even _ . has changed ; well . changed ; good. has changed ; better . changed ; better6、Zhao Lan _already _in this school for two years . was ; studying . will ; study. has ; studied . are ; studying7、We _ Xiao Li since she was a little girl . know . had known . have known . knew 8、Harry Potter is a very nice film .I_ it twice . will see . have seen . saw .see9、-These farmers have been to the United States . -Really ? When _ there ?. will they go . did they go. do they go . have they gone10、-_ you _ your homework yet ?-Yes . I _ it a moment ago . Did ; do ; finished . Have ; done ; finished. Have ; done ; have finished . will ; do ; finish11、 His father _ the Party since 1978 . joined . has joined . was in . has been in12、-Do you know him well ?- Sure .We _ friends since ten years ago . were . have been . have become . have made13、-How long have you _ here ?-About two months . been . gone . come . arrived14、Hurry up! The play _ for ten minutes . has begun . had begun . has been on. began15、 It _ ten years since he left the army . is . has . will . was16、 Miss Green isnt in the office . she_ to the library .has gone . went .will go . has been17、My parents _ Shandong for ten years . have been in . have been to. have gone to . have been18、The students have cleaned the classroom, ?A. so they B. dont they C. have the