学位英语课件-动词完成时态

1、1.现在完成时 1)现在完成时用来表示之前已发生或完成的动作或状态，其结果的确和现在有联系。动作或状态发生在过去但它的影响现在还存在；也可表示持续到现在的动作或状态。2)通常与下列状语连用，如yet，already, up to now(直到现在)， so far(到目前为止), since，for the past (last) few years等.3)其构成： have (has) +过去分词。如：Up to now，we have received no news from her. 直到现在，我们还没收到她的消息。He has worked here for over twenty

2、years. 他在这里工作已有20多年了。 比较过去时与现在完成时a.过去时表示过去某时发生的动作或单纯叙述过去的事情；现在完成时为过去发生的，强调过去的事情对现在的影响。 I saw this film yesterday.（强调看的动作发生过了。） I have seen this film. （强调对现在的影响，电影的内容已经知道了。）She has returned from Paris.她已从巴黎回来了。She returned yesterday. 她是昨天回来了。 2.过去完成时 1） 表示过去的过去 。2）其构成是had +过去分词构成。 在told, said, knew,

3、heard, thought等动词后的宾语从句。 如：She said (that) she had never been to Paris.在过去不同时间发生的两个动作中，发生在先，用过去完成时；发生在后，用一般过去时。如：When the police arrived, the thieves had run away.表示意向的动词，如hope, wish, expect, think, intend, mean, suppose等，用过去完成时表示“原本”如：We had hoped that you would come, but you didnt. This/It is the

4、first/second.timethat从句。 that从句一般用现在完成时，如果把前边的is改为was，则that从句用过去完成时。 如： It was the third time (that) he had made the same mistake.这是他第三次犯同样的错误。3.将来完成时 1)构成:will / be going to have done sth. 2) 概念 a. 状态完成：表示某事继续到将来某一时为止一直有的状态。b. 动作完成：表示将来某一时，已经完成的动作或获得的经验。 You will have reached Shanghai by this time tomorrow. They will have been married for 20 years by then.Exercises1. He _ already _ reading the book.A. has, finished B. had, finished C. will have finished2. By the end of last year, we _ 1,000 trees in the hill.A. have planted B. had planted C. will have planted3.The center _ computer