6英语现在完成时语法详细讲解与配套习题 8B Unit 1 Past and present Grammar 现在完成时 一、现在完成时用来表示之前已发生或完成的动作或状态，但它的影响现在还存在；也可表示持续到现在的动作或状态。其构成： have (has) +过去分词。规则变化的过去分词与过去式的变化一样，在动词词尾加ed; 不规则变化的过去分词见不规则动词表，需要同学记忆。 现以see the film为例将现在完成时的肯定句， 否定句和疑问句列表如下： 肯定句：I/You/We/They have seen the film. He/She /It has seen the film. 否定句：I/You/We/They have not/ havent seen the film. He/ She/It has not/hasnt seen the film. 疑问句：Have I/you/they seen the film? Yes, you/ we/I/they have. No, you/ we/I/they havent. Has he/she/it seen the film? Yes, he/ she/ it has. No, he/ she/ it hasnt. 二、用法：现在完成时既涉及过去，又联系现在。用法一：表示过去发生或已经完成的某一动作对现在造成的影响或结果。常与just（刚刚），already（已经），never（从来没有），ever（曾经），before（以前），yet（仍然），once（一次），twice（两次），many times（很多次），how many times（多少次），so far（迄今为止），during the past（last）three years（最近三年来）等连用。 副词的位置：just常用于肯定句中，放在have / has后，He has just come . never表示否定, 放在have / has后, He has never visited the Great Wall. ever用于疑问句中,句型为: Have / Has主语ever 过去分词？“曾经过吗？”用于询问某人过去的经历。Have you ever been to the farm？ before用于句末，The woman has never heard of that before. yet 用于句末或not 之后.Has the train arrived yet? No, not yet. already用于肯定句, have / has 之后或句末.We have already finished it. so far用于句首或句末. So far, we have visited the moon. 用法二：表示过去已经开始，一直延续到现在的动作或状态。时间状语有： for表示一段时间的词语I have taught English for 19 years。 since表示过去时间点的词语He has been at this school since 1986. since表示过去的时间状语从句I have lived here since I was born. since一段时间ago. I have known him since 20 years ago. 三、现在完成时态中可以和表示一段时间状语（for，since，how long, all ones life）连用的动词必须是表示延续的情况或动作的动词，即延续性动词。如：be，have，know，live，work，study，learn，teach，keep，speak，talk，draw，wait，wear，walk，sleep，drive，write，do，clean等。 I have been a teacher for nearly 20 years. How long has he lived here? 四、延续性动词的现在完成时可和包括“现在”在内的（到说话时仍未结束）表示一段时间的状语连用。如this morning，today，this week，these days He has been to Beijing three times this year. He has written two letters this morning.（说话时间在上午）He wrote two letters this morning.（说话时间在下午或晚上）、英语中还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。He has come back.（）He has come back for two hours.（） 但在否定句中，非延续性动词也可用表示一段时间的状语来修饰，如 I havent heard from my father for a long time. We havent seen him since 1999. 六、当终止性动词（非延续性动词）与表示一段时间的状语（how long，since，for， all ones 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. He has come back for two weeks.（错）改为:He came back two weeks ago.（正） I have lost my bike for ten days. （错）改为:I lost my bike ten days ago. （正） （2）用“It is / has been时间since一般过去时态”句型来改写。 He has joined the League for 3 years. （错）It is 3 years since he joined the League. I have bought the book for 5 days. （错）It is 5 days since I bought the book. （正） He has died for 20 years. （错）It is 20 years since he died. （正） （3）用“时间has passedsince一般过去时态”句型来改写。 He has left home for 20 years. 改为:Twenty years has passed since he left home. He has lost his pen for 2 days. 改为:Two days has passed since he lost his pen. （4）用系表结构来改写. He has died for 20 years. 改为: He has been dead for 20 years. The factory has opened since 1999. 改为:The factory has been open since 1999. How long has he left? 改为:How long has he been away? （5）用相应的延续性动词替代非延续性动词。 He has bought the book for two weeks. 改为:He has had the book for two weeks. 常见的相应转换形式如下: borrow / lendkeep, buyhave, finish / endbe over, arrive /come / go / move / reach /get tobe in /at / be here /be there, begin / startbe on , openbe open , closebe closed, diebe dead , leavebe away（from）, go to schoolbe in school / be a student, get upbe up, fall asleepbe asleep , fall illbe ill, get to knowknow, losebe lost, becomebe, return / come back / get backbe back, joinbe in / be amember, join the armybe in the army /be a soldier, receive / get a letterhave a letter , catch / get a coldhave a cold, begin to studystudy, 他参军已有三年.He has joined the army for three years.（错）改为: He has been in the army for three years / since three years ago. He has been a soldier for three years / since three years ago. He joined the army three years ago. It is three years since he joined the army. Three years has passed since he joined the army. （1）He came to our village two years ago.=He our village since two years ago. （2）He left home three days ago= He home for 3 days. （3）I bought the watch 2 weeks ago= I the watch since 2 weeks ago. （4）It is 5 days since I borrowed the book= I the book for 5 days. （5）The film has begun= The film for half an hour. （6）I got to know him 10 years ago= I him for 10 years. （7）There is a factory= There a factory for 2