1、现在完成时与过去完成时的区别 The present perfect tense & The past perfect tense,I have finished my homework.,I had finished my homework by 10:00 this morning.,概念,现在完成时 1.表示过去发生的对现在有影响的动作；I have seen the film many times. 2.表示过去某一时间开始一直延续到现在的动作。He has lived here since 1949. 过去完成时表示过去某一时刻以前已经开始并一直延续到这一时刻或在此刻前已经完成的动作
2、，即“过去的过去”By the end of last term we had learned 1000 English words.,形式,现在完成时have/has+动词的过去分词主语为三人称单数，则用“has+过去分词” She has waited here for an hour. 主语为非单三，则用“have+过去分词” I have waited here for an hour.,过去完成时had + 过去分词 had 可用于各种人称和数By the end of this term we had learned 1000 English words.,1.表示过去发生的某一动
3、作对现在造成的影响或产生的结果（强调是过去动作与现在的联系,也就是强调现在的影响和结果）通常与表示与包括现在在内的时间副词 just,already,before,yet,never,ever等状语连用eg.I have never heard of that before.She has already known the news.,现在完成时的用法,2.表示过去某个时间开始的动作或存在的状态，一直持续到现在并可能还将持续下去。动词使用延续性动词常与for或since引导的时间连用so far, by now, this days, in the last ten yearsfor+一段时
4、间 eg. He has lived here for 5 years.since+ （表示过去某一时间的）时间点eg. He has been here since 5 years ago.,短暂性的动词不能和for,since 连用become,begin,buy,borrow,arrive,come,know,join,leave,go,finish,fall,dieeg. The film began five minutes ago.-The film has been on for five minutes.-It has been five minutes since the f
5、ilm began. 用 how long 提问eg. How long has the film began?,过去完成时的用法,1.表示在过去某一时间以前完成的动作或事件。是一个相对的时态，强调在某一时间点或动作之前发生的动作。需要与表示过去的时间状语，不能离开过去的时间而独立存在。此时多与already,yet,still,just,before,ever,by,until 等连用eg. He had read the text before he came to school.I had finished reading the book by 10:00 last night.,2.
6、表示某一动作或状态在过去某时之前已经开始，一直延续到这一过去时间，并可能还将持续下去。eg. By the end of last year,he had work in the factory for 10 years.,过去完成时通常连用的时间状语：byby the end of + 过去的时间点before eg. He had read the text before he came to school.By the end of last year,he had work in the factory for 10 years.They had planted 100 trees b
7、efore last Sunday.,表示意向的动词如hope,wish,except,think,intend,mean,suppose 等用过去完成时表示原本想做但并未完成的动作eg. I had hoped that you would come to my party.,练 习,1.I have this nice watch for two years(A)had (B)bought (C)borrowed (D)lend2.The train from Beijing _ten minutes ago. (A)has arrived (B)was arriving (C)arrived (D)had arrived3.The famous writer _one new book in the past two years.(A)had written (B)was writing (C)wrote (D)has written4.I _900 English words by the time I was ten.(A)learned (B)was learning (C)had learned (D)learnt,
