Unit 1 Topic 1 语法专题现在完成时面面观 A、现在完成时的构成•现在完成时由“助动词have / has + 过去分 词”构成；否定式为“助动词have / has + not + 过去分词”；疑问式为“Have / Has + 过去分词 + 其他成分”如：•I have found my bike already. (肯定式)•I have not found my bike yet. (否定式)•Have you found your bike yet? (疑问式) B、现在完成时的用法•1. 表示过去发生或已经完成的动作，其后果和影响仍然存在如：•The young woman has got her money. （相当于：The young woman got her money back and she has it now.）•2. 表示从过去开始并延续到现在的动作或状态，也许还要继续进行下去常和表示一段时间的时间状语如“for + 一段时间”、“since + 表示过去的时间点”或“since + 从句”等连用 B、现在完成时的用法•也可后接表示从过去某一时刻延续到现在并包括现在的时间状语，如in the past few years, so far等连用。
如：•It has been fine for weeks. （相当于：It was fine for weeks and it is still fine now.） C、现在完成时和一般过去时的区别•1. 两者都可以表示过去发生过的动作，但现在完成时表示的是过去的动作对现在的影响，强调和现在的关系，不能和具体表示过去的时间状语连用；而一般过去时则是表示过去动作的事实，和现在无关，通常和表示过去的时间状语连用试比较：•I have lost my bike. （没有找回自行车）•I lost my bike. （曾经丢过自行车，现在可能已找到） C、现在完成时和一般过去时的区别•2. 两者都可以表示过去开始并延续了一段时间的动作，现在完成时的含义为该动作仍在继续，而一般过去时则说明该动作现已终止试比较：•My uncle has lived in London for four years. （现在仍住在那儿）•My uncle lived in London for four years. （现在不住在那儿） D、现在完成时中的延续性动词 和非延续性动词的使用•英语中有一些动词的意义决定它们所表示的动作不能延续,只是一瞬间就结束的动作,这 类动词叫做“非延续性动词”，常见的有：come, go, arrive, reach, see, hear, close, open, leave, begin, start, lose, buy, fall, join, die, get up, become, borrow, lend, find, finish, receive等。
这些动词可用于现在完成时，说明某个动作的结果还存在，但不能和表示一段时间的状语（how long, for, since）连用 D、现在完成时中的延续性动词 和非延续性动词的使用•如：•He has come back. （√） •He has come back for two hours. （×）•注意： 在否定句中，非延续性动词可用表示一段时间的状语来修饰如：•I haven’t heard from my father for a long time. •We haven’t seen him since 1999. D、现在完成时中的延续性动词 和非延续性动词的使用•当非延续性动词与表示一段时间的状语（how long, since, for, all one’s life）相矛盾时，改正错句的方法有如下几种：•（1） 用副词ago把现在完成时的句子改为一般过去时如：•He has come back for two weeks. （×） •He came back two weeks ago. （√） D、现在完成时中的延续性动词 和非延续性动词的使用•（2） 用“It is / has been + 时间 + since + 一般过去时态”句型来改写。
如：•He has joined the League for 3 years. （×）•It is 3 years since he joined the League. （√）•I have bought the book for 5 days. （×）•It is 5 days since I bought the book. （√） D、现在完成时中的延续性动词 和非延续性动词的使用•（3） 用“时间 + has passed + since + 一般过去时态”句型来改写如：•He has left home for 20 years. （×）•Twenty years has passed since he left home. （√）•（4） 用系表结构来改写如：•He has died for 20 years. （×）•He has been dead for 20 years. （√） D、现在完成时中的延续性动词 和非延续性动词的使用•The factory has opened since 1999. （×）•The factory has been open since 1999. （√）•（5） 用相应的延续性动词替代非延续性动词。
如：•He has bought the book for two weeks. （×）•He has had the book for two weeks. （√） Unit 1 Topic 1 语法专题现在完成时过关练习 I. 用所给动词的适当时态填空用所给动词的适当时态填空•1. —________ you ________ (see) the film before?•—Yes, I ________.•—Where ________ you ________ (see) it?•—At Guangming Cinema.•2. I ________ (lend) her some CDs three days ago, but she _____________ (not give) them back to me yet.Have seenhave did seelenthasn’t given •3. —How many times ________ you ________ (be) to the Great Wall?•—Only once. •4. —________ it ________ (rain) last night?•—Yes. It ___________ (rain) every day so far this month.•5. —Where’s Simon?• —He __________ (go) swimming already. He ________ (go) out ten minutes ago.have beenDid rainhas rainedhas gonewentI. 用所给动词的适当时态填空。
用所给动词的适当时态填空 II. 同义句转换，每空一词同义句转换，每空一词•1. The company opened two years ago.•The company ________ ________ ________ for two years.•2. Father joined the Party ten years ago.•Father ________ ________ ________ the Party ________ ten years.•3. Simon came here two hours ago.•Simon ________ ________ here for two hours.has beenopenhas been inforhas been II. 同义句转换，每空一词同义句转换，每空一词•4. I came to this school last year.•I ________ ________ a student of this school for a year.•5. I bought the computer in 2001.•I ________ ________ the computer ________ 2001.•6. He left home three days ago.•He ________ ________ ________ ________ home for 3 days.have beenhave hadsincehas been awayfrom II. 同义句转换，每空一词。
同义句转换，每空一词•7. It is 5 days since I borrowed the book.•I ________ ________ the book for 5 days.•8. The film began half an hour ago. •The film ________ ________ ________ for half an hour.•9. I got to know him 10 years ago.•I ________ ________ him for 10 years.•10. The little boy finished his homework just now.•The little boy ________ ________ finished his homework.have kepthas been onhave knownhas just See you ! 。