初中现在完成时讲解及习题

现在完成时定义：（1） 强调动作是过去发生的 （2） 强调对现在的影响或结果，此用法容易和一般过去时混淆。两者的区别是：一般过去时有动作发生的时间点，即过去某一时间发生某一动作；现在完成时则没有，即不强调是那个时间点发生的动作，而强调过去的动作对现在造成的影响和结果。 （3） 在过去不确定的时间里发生的动作，但是结果对现在有影响。现在完成时表示过去发生或已经完成的动作对现在造成的影响或结果,也可表示过去已经开始,一直延续到现在的动作或状态。学习现在完成时,先从结构和句式开始:构成:主语 + have/has + 过去分词 + 其他。(当主语是第三人称单数时用has,其余人称用have。过去分词:规则动词的过去分词构成与动词过去式相同;不规则动词需要特殊记忆。)否定式:主语 + havent/hasnt + 过去分词 + 其他。疑问式: Have /Has + 主语 + 过去分词 + 其他? 特殊疑问句：特殊疑问词或词组+一般疑问句（have/has+主语+过去分词+其他）简略答语: Yes, 主语 + have/has.(肯定)No, 主语 + havent/hasnt.(否定)标志词：* 以already, just和yet为标志 already, just和yet 表示到现在为止动作或状态已经、刚刚或还没有发生。 * 以ever和never为标志ever和never 表示到现在为止动作或状态曾经或从来没有发生过。 * 以动作发生的次数为标志若某一动作到现在为止已经发生了若干次,则要使用现在完成时。 * 以so far为标志so far往往表示到目前为止动作或状态已经发生。第三部分过去已经开始的动作一直延续到现在, 甚至有可能继续延续下去,我们可以从动作“延续”的特性和“时间”点段的区分入手,进一步学习现在完成时。英语中的动词从词义上可以分为延续性和非延续性两种,在现在完成时态中一定要注意动词这一特性,应将这类非延续性动词转换为延续性动词。* 时间“点”、“段”须分清过去开始的动作可以延续到某一点结束,也可能继续延续,这时就要根据时间“点”、“段”选择相应的介词for或since。第四部分 一、动词的过去分词形式：通常一个动词的过去分词和他的过去式是一样的，在动词后面加ed构成过去分词，但是有一些动词的过去分词有不规则的形式。 二、当have被用在现在完成时态中时，它可以和前面的代名词一起组成缩写形式。 三、现在完成时用not来表达否定形式。当有not出现的时候，have可以和not组成缩写，但是此时不能和前面的代名词组成缩写。（1）现在完成时用来表示现在之前已发生过或完成的动作或状态,但其结果却和现在有联系,也就是说,动作或状态发生在过去但它的影响现在还存在，也就是说，动作发生在过去，而对现在造成的影响和结果. I have spent all of my money.(现在我没有钱花了.) Jane has laid the table.(现在桌子已经摆好了.)（2）现在完成时可以用来表示发生在过去某一时刻的,持续到现在的动作（用行为动词表示）或状态（be动词表示）常与for（+时间段）,since（+时间点或过去时的句子）连用. for+时段 为时间 since+过去一个时间点（译为：自从以来） since+时段+ago since+从句（过去时） It is+时段+since+从句（过去时） Mary has been ill for three days. I have lived here since 1998.注意;1.现在完成时不能单独与准确时间连用，(如表示过去的时间状语） 如yesterday(morning、afternoon),last(morning、afternoon)等，除非与for,since连用. 2.现在完成时往往同表示不确定的过去时间状语连用 如already（肯定）, yet（否定，疑问）, just, before, recently,still, lately,never等: He has already obtained a scholarship. I havent seen much of him recently (lately). We have seen that film before. Have they found the missing child yet ? 3. 现在完成时常常与表示频度的时间状语连用, 如often, sometimes, ever, never, twice, on several occasion等: Have you ever been to Beijing I have never heard Bunny say anything against her. I have used this pen only three times. It is still good. George has met that gentleman on several occasions. 4. 现在完成时还往往可以同包括现在时间在内的时间状语连用, 如now, up to these few days/weeks/months/years, this morning/week/month/year, just, today, up to present, so far等: Peter has written six papers so far. Man has now learned to release energy from the nucleus of the atom. There has been too much rain in San Francisco this year. The friendly relations and cooperation between our two countries have been enhanced in the past few years. Up to the present everything has been successful. 5. 现在完成时还可以用来表示过去的一个时间到现在这段时间内重复发生的动作. We have had four texts this semester. 6.现在完成时的完成用法 现在完成时的完成用法指的是动作发生在过去某一时刻并已结束，但该动作对现在产生了影响，与现在情况具有因果关系。 例如：He has turned off the light.他已把灯关了。(动作结束于过去，但说明的是现在的情况-灯现在不亮了。) 现在完成时完成用法的特点是动作不延续，因此，该时态只能与表示不定的过去时间状语(如：already，yet，before，recently等)、频度时间状语(如：never，ever，once等)、包括现在时刻在内的时间状语(如：this morning month year.，today等)连用。 例如： Have you found your pen yet？你已找到你的钢笔了吗？ 7.现在完成时的未完成用法 现在完成时的未完成用法指的是动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。 例如：He has lived here since 1978.自从1978年以来，他一直住在这儿。(动作起始于1978年，一直住到现在，可能还要继续住下去。) I have been in the army for more than 5 years.我在部队已经呆了五年多了。(动作开始于5年前，一直延续至今，有可能还要继续下去。) 此种用法的句中常需一个表示一段时间的状语(由since或for引导)，或表示与现在时刻相连的时间状语(如：up to now，so far)等。 例如：I have heard nothing from him up to now.到目前为止我没有他的任何消息。 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。 8.一段时间+has passed+since从句 9. 现在完成时常和短语 up to now /till now, so far (意思是从过去某一确定的时间一直延续到现在.) Up to/till now hes read many story books. 至今他已读过好多故事书。 Ive been to New York three times so far. 至今我已到纽约去过三次。 10 has gone (to),has been (to), has been (in) 的区别 gone:去了没回 been to :去过 been in：呆了很久 10.不能与when连用练习 B.1.Mother _me a new coat yesterday. I _ it on. It fits me well.A. had madehave tried B. madehave triedC. has madetried D. madetriedD.2 “He _to draw horses already”. “When _ he ?” “ Last year “ A. learnedhas B. learneddid C. has learnedhas D. has learneddidA.3.Tom _up into the tree. Look, he _ high up there !A. has gotis B. has climbedwas C. got was D. climbedisC.4._ you _ the text yet ? Yes, we _ it two hours ago.A. Didcopydid B. Havecopiedhave C. Havecopieddid D. Did copyhadA.5. “Why _ she _ angry ?” “Because he _ at her just now .”A. didgetshouted B. hasgotshouted C. didgethas shouted D. hasgothas shoutedA.6. _you _ the film before ? Where _ you _ it ?A. Have seendidsee B. Did seedidwatchC. Haveseenhaveseen D. Did seehaveseenD.7.You _ me waiting for two hours. I _ for you since five.A. keptwaited B. have keptwaited C. kepthave waited D. have kepthave waitedB.8.Where _ John _ ? To the library. He _ there for an hour.A. hasbeenhas gone B. hasgonehas been C. didgowent D. didbewentD.9._ the baby still _ ? No, it _ crying.A. Hascriedhas stopped B. Iscryingstopped C. Did crystopped D. Iscryinghas stoppedC.10. I _ the way. I _ here for quite many years.A. knewhave lived C. knewlive C. knowhave lived D. knowliveC.11. _ you ever _ America ? Yes, I have.A. Havegone to B. Havegone in C. Havebeen to D. Have been inD.12. My brother _college for over three years.A. has gone to B. has been to C. has been in D. has been atD.13.He _ the Army by the end of 1989. He _ in the army since then.A. joinedis B. has joinedhas been C. had joinedis D. had joined has beenB.14. By the time I _ back they _ up ten satellites.A. camehave sent B. camehad sent C. comehave sent D. had comesentC.15. Jack _ over five lessons by seven oclock. Then he _ a rest.A. wenttook B. wenthad taken C. had gonetook D. had gonehad takenA.16. We _ out by that time that he _ a spy for a long time.A. had foundhad been B. had foundwas C. foundhad been D. foundwasB.17. Before the news _ him, he _ to know about it.A. reacheshas got B. reachedhad got C. reachedgot D. had reachedgotC.18. I _ him a second letter before I _ from him.A. wroteheard B. wrotehad heard C. had writtenheard D. have writtenhearD.19. People _ that the soldiers _ fighting.A. sayhad