知识点总结现在完成时：其构成： have (has) +done 用法： 1）表示过去发生的动作对现在的影响或结果； I’ve seen the film Avatar before. 2）表示持续到现在的动作或状态。 They’ve lived there for eleven years. 比较过去时与现在完成时 1）过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时强调过去的事情对现在的影响，强调的是影响。 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。） 2）过去时常与具体的时间状语yesterday, last week，…ago, in1980, in October, just now等连用，而现在完成时通常与模糊的时间状语for, since, so far, ever, never, just, before, yet, till / until, up to now, in past years, always等连用，或无时间状语。 共同的时间状语: this morning, tonight, this April, now, once，before, already, recently，lately 3）现在完成时可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. 过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等。 用于现在完成时的句型 1）It is the first / second time…. that… It is the first time that I have visited the city. 2）This is the… that… This is the best film that I''ve (ever) seen. 注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。 I haven''t 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 since 1949. 注意：并非有for 作为时间状语的句子都用现在完成时。 I worked here for more than twenty years. (我现在已不在这里工作。) I have worked here for many years.(现在我仍在这里工作。) 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； 瞬间动词表示行为的结果，不能与表示段的时间状语连用。 He has completed the work. (表结果) I''ve known him since then. (表经历) 2)用于till / until从句的差异 延续动词用于肯定句，表示"做……直到……"； 瞬间动词用于否定句，表示"到……，才……" He didn''t come back until ten o''clock. He slept until ten o''clock. 常见考法1.把考察放在从句中增加难度；2.和被动语态放在一起考察；3.根据状语确定时态4.用现在完成时的句型 误区提醒1.现在完成和一般过去弄混；2.现在完成时的句型不熟悉；3. 不能根据状语选定现在完成时。 【典型例题】 1. You don''t need to describe her. I ___ her several times. A. had met B. have met C. met D. meet 解析：错选C。首先本题后句强调对现在的影响，我知道她的模样，你不用描述；再次，“several times” 表示“（到目前为止）我（已经）见过她 “好几次”了，因此用现在完成时，答案B。 2. ---I''m 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 解析：错选C。等待的动作由过去开始，持续到现在，应用现在完成时，答案A。 3. ---Do you know our town at all? ---No, this is the first time I ___ here. A. was B. have been C. came D. am coming 解析：错选D。This is the first time 后面所加从句应为现在完成时，答案B。 |
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