造成影响和不造成影响能帮我理解一下吗?谢谢了,大神帮忙啊

发布网友发布时间：2024-10-23 11:12

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热心网友时间：2024-10-23 14:49

给你粘一个别人的答案，关于过去完成时用法的。过去完成时用法讲解 1、概述过去完成时表示过去某一时间或动作以前已经发生或完成了的动作。它表示动作发生的时间是“过去的过去”。表示过去某一时间可用by, before等构成的短语，也可用when, before等引导的从句或通过上下代表示。 His eyes shone brightly when he finally received the magazine he had long expected. 当她终于收到她盼望已久的杂志时，她兴奋得两眼闪光。 By the time he was twelve, Edison had begun to make a living by himself.12岁时，爱迪生就开始自己谋生。 2、构成过去完成时由“助动词had+过去分词”构成。其否定式、肯定式、疑问式如下表：肯定式否定式疑问式 I(we) I(We) you You had read it. had not read it Had they read it? He(She, They) He(She ,They) he 注意：had not 常简略为hadn't。 They asked me to have a drink with them and said it was at least ten years since I had enjoyed a good drink. 他们请我和他们一起喝酒，并说我自上次喝酒到现在至少十年了。 We had learnt 30 lessons by the end of last month.到上个月末为止，我们已经学了30课。 He said we hadn’t seen each other since I left Beijing.自从我离开北京，我们还没见过面。 3、过去完成时的用法过去完成时的主要用法和现在完成时一样。不同的是，过去完成时把时间推移到了过去某一时间之前，与现在无关。（1）过去完成时表示在过去某一时间或动作以前已经完成了的动作。这个过去的时间状语有by, before等介词短语或when, before等引导的从句。 Helen had left her keys in the office so she had to wait until her husband came home. 海伦把钥匙忘到办公室里了，因此她不得不等她丈夫回来。 When we got to the cinema, the film had already begun.当我们到达电影院时，电影已经开始了。 He told me that he had visited the Great Wall before.他告诉我他以前参观过长城。 By the end of the match, they had kicked 2 goals, and we had kicked 4.比赛结束时，他们踢进了2个球而我们踢进了4个球。 When Jack arrived he learned Mary had been away for almost an hour.杰克到达后得知玛丽走了近一个小时了。（2）表示动作在过去某一时间之前开始，一直延续到过去的这一时间，而且还可能继续下去的动作，常和for, since构成的短语或引导的从句连用。 The news came as no surprise to me. I had known for some time that the factory was going to shut down. 听到这个消息我并不感到吃惊。工厂要倒闭这件事我早就知道了。 By the time I left the school, he had taught the class for 3 years.到我毕业时，他已经教那个班三年了。 He said he had made great progress since he came here.他说自从他来这里他已经取得了很大进步。（3）用于表示与过去事实相反的虚拟条件从句或as if从句中表示与过去事实相反 If he had seen you yesterday, he would have asked you about it.假如他昨天看到你，他就会问你这件事了。 I should have called you if I had known your telephone number.假如我过去知道你的电话号码，我就给你打电话了。 He described the scene as if he had been there.他描绘的景色如同他去过那里一样。 Had I known that you wanted the book, I would have sent it.如果我知道你要这本书，我会送来的。（4）表示假设的宾语从句放在像said，told，asked，thought，wondered等过去时动词的后面，表示在这些动作发生之前已经发生了的事情。 My friend told me that he had passed the exam.我的朋友告诉我，他已通过了考试。 He asked me whether I had seen the film the night before.他问我头一天晚上是否看过那部电影。 She wondered who had left the door open.她想知道谁敞着门的。（5）用在 "It was the first/second/third…time that…”句型中在此句型中，主句用了一般过去时，that引导的定语从句要用过去完成时。 This was the first time they had met in thirty-nine years. 这是39年里他们第一次见面。 It was the first time we had spoken together. 这是我们第一次在一起说话。（6）intend, mean, hope, want, plan, suppose, expect, think等动词的过去完成时可以表示一个本来打算做而没有做的事这种结构也可以表示过去未曾实现的设想、意图或希望等，含有某种惋惜。 I had intended to call on you yesterday, but I had an unexpected visitor.我本来昨天打算要去看你，但我来了个不速之客。 We had meant to tell her the news but found that she wasn’t in.我们本想把这个消息告诉她的，但发现她不在家。（7）过去完成时常用结构有“hardly, scarcely, barely … when, no sooner… than等副词的句子里。 She hardly had gone to bed when the bell rang.他刚睡下铃就响了。 No sooner had they left the building than a bomb exploded.他们刚刚离开大楼，一颗炸弹就爆炸了。（8）当before , after, as soon as 等引导的从句里的动作与主句的动作紧接时，由于这些连词本身已经说明了两个动作发生的先后关系，因此两个动作均可用一般过去时表示。 We had breakfast after we did morning exercises.做完早操之后，我们吃早饭。 The train started to move just before we reached the station.我们到车站时火车刚开动。 As soon as they got there, they started to study.他们一到那里就开始学习了。