现在完成时的结构(共4页).doc

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1、精选优质文档-倾情为你奉上现在完成时的结构由“have/has+”构成，主要有两个含义：表示动作发生在，但与的情况有联系，有时无，有时和一些表示不确定的过去连用，如：many times，just，yet，ever，never，already，before，so far, by now等连用。表示从某一时间开始一直延续到并还可能继续延续下去的动作，用于，且句中常带有表示一段时间的，如：since + 时间点/，for two months, so far等。二 、1）和都能表示过去发生过的动作，但现在完成时表示过去动作对现在的影响，并且表示这一动作已完成或还可能继续下去；2）而一般过去时与现在

2、的情况没有联系，仅表示过去的动作，且这一动作到说话时已终止。因此不能与表示明确的时间如：in1949，yesterday，last week等的连用，并且用when或where对这些时间和提问时，一般只用。三、在“it is first/secondtime that。”或在“it/this/that is the +最高级+名词+that.。”结构中，that中的动词常用；在“it + be +since从句”这一结构中，be可用或现在完成时，since从句一般用时。have/has/had +been +动词的现在进行时比较过去时与现在完成时1）时表示过去某时发生的动作或单纯叙述过去的事情

3、，强调动作；为过去发生的，强调过去的事情对现在的影响，强调的是影响。 2）时常与具体的连用，而通常与模糊的连用，或无时间状语。的时间状语:yesterday, last week，ago, in1980, just now, 具体的共同的:this morning, tonight, this April, now, once，before, already, recently，lately的for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,不确定的时间状语3）可

4、表示持续到现在的动作或状态，动词一般是延续性的，如live, teach, learn, work, study, know. 时常用的有come, go, leave, start, die, finish, become, get married等。举例：I saw this film yesterday.（强调看的动作发生过了。）I have seen this film. （强调对的影响，电影的内容已经知道了。）Why did you get up so early?（强调起床的动作已发生过了。）Who hasnt handed in his paper?（强调有卷子，可能为不公平竞争

5、。）She has returned from Paris.她已从回来了。She returned yesterday. 她是昨天回来了。He has been in the League for three years.(在团内的状态可延续)He has been a League member for three years.(是团员的状态可持续)He joined the League three years ago.( 三年前入团，joined为短暂行为。)I have finished my homework now.-Will somebody go and get Dr. Whi

6、te?-Hes already been sent for.句子中如有时的时间（如 yesterday, last, week, in 1960）时，不能使用，要用过去时。（错）Tom has written a letter to his parents last night.（对）Tom wrote a letter to his parents last night.用于现在完成时的句型1）It is the first / second time. that结构中的部分，用。It is the first time that I have visited the city.It was

7、 the third time that the boy had been late.2）This is the that结构，that 要用.This is the best film that Ive (ever) seen. 这是我看过的最好的电影。This is the first time (that) Ive heard him sing.这是我第一次听他唱歌。典型例题(1) -Do you know our town at all?-No, this is the first time I _ here.A. was B. have been C. came D. am comi

8、ng 答案B. This is the first time 后面所加应为，故选B。(2) -Have you _ been to our town before?-No, its the first time I _ here.A. even, come B. even, have come C. ever, come D. ever, have come答案D. ever意为曾经或无论何时，反意词为never，此两词常用于完成时。 This is the largest fish I have ever seen. It is / was the first time +that-clau

9、se 的句型中，要用完成时。注意：的否定形式可以与表示延续时间的连用。即动作不发生的状态是可以持续的。（错）I have received his letter for a month.（对）I havent received his letter for almost a month.比较since和for Since 用来说明动作起始时间，for用来说明动作延续时间长度。I have lived here for more than twenty years.I have lived here since I was born.My aunt has worked in a clinic

10、since 1949.Some new oilfields have been opened up since 1976. I have known Xiao Li since she was a little girl.My brother has been in the Youth League for two years.I have not heard from my uncle for a long time.注意：并非有for 作为的句子都用。I worked here for more than twenty years. (我已不在这里工作。)I have worked her

11、e for many years.(我仍在这里工作。)小窍门：当+一段时间，这一结构中，我们用下面的公式转化，很容易就能排除非延续动词在完成时中的误使。1)(对) Tom has studied Russian for three years.= Tom began to study Russian three years ago, and is still studying it now.2)(错) Harry has got married for six years.= Harry began to get married six years ago, and is still gett

12、ing married now.显然，第二句不对，它应改为 Harry got married six years ago.或 Harry has been married for six years.since的四种用法1) since +一个时间点(如具体的年、月、日期、1980, last month, half past six)。I have been here since 1989.2) since +一段时间+ agoI have been here since five months ago.3) since +从句Great changes have taken place

13、since you left.Considerable time has elapsed since we have been here. 4) It is +一段时间+ since从句It is two years since I became a postgraduate student.延续动词与瞬间动词1) 用于完成时的区别延续动词表示经验、经历； 表示行为的结 果，不能与表示段的连用。He has completed the work.他已完成了那项工作。 (表结果)Ive known him since then. 我从那时起就认识他了。(表经历)2)用于till / until的

14、差异作为延续动词一般用于肯定句，表示做直到 作为瞬间动词一般用于否定句，表示到，才He didnt come back until ten oclock. 他到10 点才回来。He slept tll ten oclock.他一直睡到10点。典型例题1. You dont need to describe her. I _ her several times.A. had met B. have met C. met D. meet答案B. 首先本题后句强调对的影响，我知道她的模样，你不用描述。再次，several times告知为反复发生的动作，因此用。2.-Im sorry to keep you waiting.-Oh, not at all. I _ here only a few minutes.A. have been B. had been C. was D. will be答案A. 等待的动作由开始，持续到，应用。专心-专注-专业