现在完成时-ppt教程文件

1、现在完成时-pptLook at These Sentences I have finished all my homework. I have cleaned all the rooms. I have eaten up all the food. You have ruined my precious flowers. 1.我把所有的功课都做完了。 2.我把所有的房间都打扫了。 3.我把所有的食物都吃光了。 4.你把我珍贵的花毁了。 基本结构和概念表示过去发生并且已经完成的动作对现在造成的影响或后果；过去某一时间开始并一直持续到现在，并且有可能还会持续的动作或状态。基本结构：主语+have

2、/has+done(动词的过去分词） 否定句：主语+have/has+not+done（过去分词）+其他 一般疑问句：Have/Has+主语+done（过去分词）+其他 简单答语：Yes,主语+have/has.（肯定） No,主语+havent/hasnt（否定）过去分词 分规则变化和不规则变化两种。不规则变化需逐个记忆，规则变化遵循以下原则： 一、规则动词一、规则动词： (1) 一般情况下，在动词后加ed构成：work / worked, stay / stayed, shout / shouted等。 (2) 在以-e结尾动词后只加d：close / closed, like / lik

3、ed, live / lived, smile / smiled等。 (3) 以辅音字母加y结尾的动词，应将y改为i 再加-ed：study / studied, carry / carried等。 (4) 以重读闭音节或r音节结尾且末尾只有一个辅音字母动词，要双写末尾的辅音字母再加-ed：stop / stopped, admit / admitted, refer / referred, prefer / preferred等。 二、不规则动词二、不规则动词 AAA型 hurt hurt hurt cut cut cut AAB型 become became become come cam

4、e come ABB型 bring brought brought buy bought bought stand stood stood ABC型 break broke broken grow grew grown 三、瞬间动词三、瞬间动词 瞬间动词(buy, die, come ,go, leave)与 for,since连用，要改变动词 buy-keep, have come-be in leave-be away begin-be on finish-be over die-be dead return-be back join-be in open-be open close-be

5、 closed功能一：表示影响 表示一个过去发生的动作在过去已经完成，并且这个过去发生并完成的动作对现在有影响或结果，同时说话者强调的或感兴趣的就是这个影响或结果。 eg: He has left the city. 他已离开这个城市。（结果：他不在这个城市） eg: I have lost my pen. 我把钢笔丢了。(结果：我现在无钢笔用） She has washed her clothes. She has done her homework. She has watered the flowers. She has swept the floors. They have watch

6、ed TV.功能二：表示持续 表示一个过去发生的动作或开始的状态在过去并未完成或结束，而是一直持续到现在并且有可能继续下去，也可能到此结束。常与for（+时间段），since（+时间点或过去时的句子）连用。 eg: He has been busy since last week. 自上个星期以来他一直很忙。 eg: He has taught in our school for 30 years. 他在我们学校教书已有30年了。功能三：表示重复 表示从过去某个时间直到现在的这个时间范围内不断重复发生的动作或情况，并且这个不断重复的动作有可能继续下去，也有可能到现在就结束。 eg: My fa

7、ther has always gone to work by bike. 我父亲一直骑车上班。注意： 1.现在完成时的未完成用法只适用于延续性动 词，不可用于终止性动词，即瞬间完成或延续 时间很短的动词。如：come，go，arrive ，leave，join，become ，die等。 2.句中标志词：already（肯定）, yet（否定，疑 问）, just, before, in the past few days/weeks/months/years, so far，up to now ,till now, since+点时间，for+段时间，since+段时 间+ago，sinc

8、e+从句(过去时），It is+时段+since+ 从句（过去时）。 Practice 1.有人把窗户打破了。（broken) Someone _ _ the window. 2.他把灯关了。（turned off） He _ _ _ the light. 3.自从1978年以来,他一直住在这儿。（lived) He _ _ here since 1978. 4.我经常周末做作业。（done) I _ _ _ my homework at weekends.has brokenhas turned offhas livedhave always doneChoose the Right One 1.a. It has died for two days. b. It has been dead for two days 2.a. The bus has left for 20 minutes. b. The bus has been away for 20 minutes. 3.a.Ben has been a teacher for 4 years. b.Ben has become a teacher for 4 years. 4.a. I have been back home for a week. b. I have returned home for