1、单元语法小专题(Grammar Focus)语法精讲过去完成时1过去完成时的概念过去完成时表示在过去的某一时间或动作之前已经完成的动作，即表示“过去的过去”。2过去完成时的句式结构过去完成时是由“助动词had动词的过去分词”构成的，had用于各种人称和数。(1)肯定句：主语had动词的过去分词其他(2)否定句：主语hadnot动词的过去分词其他(3)一般疑问句：Had主语动词的过去分词其他？肯定回答：Yes，主语had.否定回答：No，主语hadnt.(4)特殊疑问句：特殊疑问词(组)一般疑问句？【拓展】被动语态：主语had (not)been动词的过去分词其他3过去完成时的判断依据(1)由时
2、间状语来判定一般说来，各种时态都有特定的时间状语。与过去完成时连用的时间状语有by，by the end of，“before过去的时间点”，“by the time一般过去时从句”等。如： I had finished reading the novel by nine oclock last night.到昨天晚上九点钟，我已经读完这部小说了。We had learned over 2，000 English words by the end of last term.到上学期结束时，我们已经学了2，000多个英语单词了。The bus had already left by the ti
3、me/when I got there.我到达那里时，公共汽车已经离开了。(2)由“过去的过去”来判定 过去完成时表示“过去的过去”，是指过去某一动作之前已经发生或完成的动作，即动作有先后关系，动作在前的用过去完成时，在后的用一般过去时。这种用法常出现在宾语从句或状语从句中。当宾语从句的主句为一般过去时，且从句的动作先于主句的动作时，从句要用过去完成时。如：She said that she had seen the film before.她说她以前看过这部电影。在表示时间、条件、原因、方式等状语从句中，主句和从句的动作发生有先后关系，动作在前的要用过去完成时，动作在后的要用一般过去时。如：
4、After he had finished his homework，he went to bed.他完成作业后就上床睡觉了。【注意】 before或after 引导的时间状语从句中，由于 before 和 after 本身已表达了动作的先后关系，若主句和从句表示的动作紧密相连，则主句和从句都可以用一般过去时。如：Where did you study before you came here？你来到这儿前在哪儿学习？After he closed the door，he left the classroom.他关上门后就离开了教室。(3)根据上下文来判定。 如：I met Wang Tao
5、in the street yesterday.We hadnt seen each other since he went to Beijing.我昨天在街上碰见王涛了。自从他去了北京，我们就没见过面了。4过去完成时的主要用法(1)过去完成时表示一个动作或状态在过去某一时间或动作之前已经完成或结束，即发生在“过去的过去”。如：When I woke up，it had stopped raining.我醒来时，雨已经停了。(“雨停”发生在“我醒来”之前) (2)过去完成时是一个相对的时态，表示的是“过去的过去”，只有和过去某一时间或某一动作相比较时才使用它。如： He told me tha
6、t he had written a new book.他告诉我他写了一本新书。(“写书”发生在“告诉我”之前) (3)过去完成时需要与一个表示过去的时间状语连用，它不能离开过去时间而独立存在。此时多与already，yet，still，just，before，never等时间副词及 by，before，until等引导的短语或从句连用。如： Peter had collected more than 300 Chinese stamps by the time he was ten.彼得到10岁的时候已经收集了300多张中国邮票。(4)过去完成时表示某一动作或状态在过去某时已经开始，一直延续
7、到某一过去时间，而且动作尚未结束，仍然有继续下去的可能。如：By the end of last year，he had worked in the factory for twenty years.到去年年底为止，他已经在这个工厂工作了20年。(已经工作了 20 年，还有继续进行下去的可能)5过去完成时与一般过去时的区别(1)时间状语不同：过去完成时在时间上强调“过去的过去”；而一般过去时只强调过去某一特定的时间。试比较： They had already left when I arrived.我到达时他们已经离开了。(在“到达”这一动作之前，他们就已经“离开”了，因此用had left表
8、示)I saw him in the street yesterday.昨天我在街上看见他了。(“看见他”这一动作是在“昨天”这一过去的时间发生的)(2)在没有明确的过去时间状语作标志时，谓语动词动作发生的时间先后须依据上下文来判断：先发生的用过去完成时，后发生的则用一般过去时。如： When I woke up，it had already stopped snowing.我醒来时雪已经停了。6过去完成时与现在完成时的区别过去完成时与already，ever，just，never，“since时间点”，“for时间段”等连用时，强调事件发生的先后顺序，不涉及现在的情况。现在完成时强调的是“过
9、去的动作或状态对现在造成的影响”。如：She has worked in Chongqing for over two years.她已经在重庆工作两年多了。(现在仍在那儿工作)She had worked in Chongqing for over two years before she moved to Shanghai.她在搬到上海之前已经在重庆工作两年多了。(“搬到上海”是过去，“在重庆工作”发生在过去的过去)He has never seen such an interesting film before.他以前从未看过这么有趣的电影。(“看”尽管发生在过去，但涉及现在，即现在已经
10、知道或了解了这部电影)He said he had never seen such an interesting film before.他说他以前从没看过这么有趣的电影。(“他说”发生在过去，“看过”是在“说”之前，是过去的过去)语法精练.用括号内所给单词的适当形式填空。1By the time I reached home，my mother had_cooked(cook) supper already.2Catherine had_finished(finish) the letter before her mother came into her bedroom.3The train
11、 had_left(leave) when I got to the station.4The little girl has_lain(lie) in bed for almost a month since she fell(fall) sick.5By the end of last year，he had_learned/learnt(learn) 3，000 English words.6It was the third time that the girl had_invited(invite) him.7I hadnt_found(not find) the dog until
12、last night.8He told his mother that he had_run(run) out of money to buy new clothes.9Tom said that he had_kept(keep) the book for two weeks.10I suddenly remembered that I had_left(leave) the key in my classroom when I got(get) home yesterday.按要求完成句子，每空一词。11By the time she got up，her mother had_gone_
13、to_work(对画线部分提问) What had her mother done by the time she got up?12When I got home，my mother had cooked dinner.(改为否定句)When I got home，my mother hadnt cooked dinner.13The train had left when I got to the station.(改为一般疑问句) Had the train left when you got to the station?14John had never seen the film b
14、efore.(改为反意疑问句)John had never seen the film before, had he?15She had already finished her homework.(改为否定句)She hadnt finished her homework yet.根据汉语意思完成句子，每空一词。16我返回学校的时候，铃声已经响了。 By the time I got back to school，the bell had rung17我到那儿时，比赛已进行了半个小时。The match had been on for half an hour when I got there.18十分钟前她没有完成家庭作业。She didnt finish her homework ten minutes ago.19我们已经看过这部电影了。 We have seen the movie.20她已经离开她的家乡很多年了。She has been away from her hometown for many years.
