【正文】 過去的事情，強(qiáng)調(diào)動(dòng)作；現(xiàn)在完成時(shí)為過去發(fā)生的，強(qiáng)調(diào)過去的事情對(duì)現(xiàn)在的影響，強(qiáng)調(diào)的是影響。 2）過去時(shí)常與具體的時(shí)間狀語連用，而現(xiàn)在完成時(shí)通常與模糊的時(shí)間狀語連用，或無時(shí)間狀語。 一般過去時(shí)的時(shí)間狀語 : yesterday, last week， …ago, in1980, in October, just now, 具體的時(shí)間狀語 共同的時(shí)間狀語 : this morning, tonight,this April, now, once， before, already, recently， lately 現(xiàn)在完成時(shí)的時(shí)間狀語 for, since, so far, ever, never, just, yet,till / until, up to now, in past years, always, 不確定的時(shí)間狀語 3）現(xiàn)在完成時(shí)可表示持續(xù)到現(xiàn)在的動(dòng)作或狀態(tài)，動(dòng)詞一般是延續(xù)性的，如 live, teach, learn, work, study, know. 過去時(shí)常用的非持續(xù)性動(dòng)詞有 e, go, leave, start, die, finish, bee, get married 等。 舉例： I saw this film yesterday. （強(qiáng)調(diào)看的動(dòng)作發(fā)生過了。） I have seen this film. （強(qiáng)調(diào)對(duì)現(xiàn)在的影響，電影的內(nèi)容已經(jīng)知道了。） Why did you get up so early? （強(qiáng)調(diào)起床的動(dòng)作已發(fā)生過了。） Who hasn39。t handed in his paper?（強(qiáng)調(diào)有卷子，可能為不公平競(jìng)爭(zhēng)。） She has returned from Paris. 她已 從巴黎回來了。 She returned yesterday. 她是昨天回來了。 He has been in the League for three years. (在團(tuán)內(nèi)的狀態(tài)可延續(xù) ) He has been a League member for three years. (是團(tuán)員的狀態(tài)可持續(xù) ) He joined the League three years ago. ( 三年前入團(tuán)， joined 為短暫行為。 ) I have finished my homework now. Will somebody go and get Dr. White? He39。s already been sent for. 句子中如有過去時(shí)的時(shí)間副詞（如 yesterday, last, week, in 1960）時(shí)，不能使用現(xiàn)在完成時(shí)，要用過去時(shí)。 （錯(cuò)） Tom has written a letter to his parents last night. （對(duì)） Tom wrote a letter to his parents last night. 用 于現(xiàn)在完成時(shí)的句型 1） It is the first / second time…. that… 結(jié)構(gòu)中的從句部分，用現(xiàn)在完成時(shí)。 It is the first time that I have visited the city. It was the third time that the boy had been late. 2） This is the… that… 結(jié)構(gòu)， that 從句要用現(xiàn)在完成時(shí) . This is the best film that I39。ve (ever) seen. 這是我 看過的最好的電影。 This is the first time (that) I39。ve heard him 。 典型例題 (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 ing 答案 B. This is the first time 后面所加從句應(yīng)為現(xiàn)在完成時(shí)，故選 B。 4 (2) Have you ____ been to our town before? No, it39。s the first time I ___ here. A. even, e B. even, have e C. ever, e D. ever, have e 答案 D. ever 意為曾經(jīng)或無論何時(shí)，反意詞為 never，此兩詞常用于完成時(shí)。 This is the largest fish I have ever seen. It is / was the first time +thatclause 的句型中，從句要用完成時(shí)。 注意：非延續(xù)性動(dòng)詞的否定形式可以與表示延續(xù)時(shí)間的狀語連用。即動(dòng)作不發(fā)生的狀態(tài)是可以持續(xù)的。 （錯(cuò)） I have received his letter for a month. （對(duì)） I haven39。t received his letter for almost a month. 比較 since 和 for Since 用來說明動(dòng)作起始時(shí)間， for 用來說明動(dòng)作延續(xù)時(shí)間長度。 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. 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 作為時(shí)間狀語的句子都用現(xiàn)在完成時(shí)。 I worked here for more than twenty years. (我現(xiàn)在已不在這里工作。 ) I have worked here for many years. (現(xiàn)在我仍在這里工作。 ) 小竅門：當(dāng)現(xiàn)在完成時(shí) +一段時(shí)間，這一結(jié)構(gòu)中，我們用下面的公式轉(zhuǎn)化，很容易就能排除非延續(xù)動(dòng)詞在完成時(shí)中的誤使。 1)(對(duì) ) Tom has studied Russian for three years. = Tom began to study Russian three years ago, and is still studying it now. 2)(錯(cuò) ) Harry has got married for six years. = Harry began to get married six years ago, and is still getting married now. 顯然，第二句不對(duì)，它應(yīng)改為 Harry got married six years Harry has been married for six years. since 的四種用法 1) since +過去一個(gè)時(shí)間點(diǎn) (如具體的年、月、日期、鐘點(diǎn)、 1980, last month, half past six)。 I have been here since 1989. 2) since +一段時(shí)間 + ago I have been here since five months ago. 3) since +從句 Great changes have taken place since you left. Considerable time has elapsed since we have been here. 4) It is +一段時(shí)間 + since 從句 It is two years since I became a postgraduate student. 延續(xù)動(dòng)詞與瞬間動(dòng)詞 1) 用于完成時(shí)的區(qū)別 延續(xù)動(dòng)詞表示經(jīng)驗(yàn)、經(jīng)歷； 瞬間動(dòng)詞表示行為的結(jié) 果，不能與表示段的時(shí)間狀語連用。 He has pleted the 。 (表結(jié)果 ) I39。ve known him since then. 我從那時(shí)起就認(rèn)識(shí)他了。 (表經(jīng)歷 ) 2)用于 till / until 從句的差異 延續(xù)動(dòng)詞用于肯定句，表示 做 …… 直到 …… 瞬間動(dòng)詞用于否定句，表示 到 …… ，才 …… He didn39。t e back until ten o39。clock. 他到 10 點(diǎn)才回來。 He slept until ten o39。clock. 他一直睡到 10 點(diǎn)。 典型例題 1. You don39。t need to describe her. I ___ her several times. A. had met B. have met C. met D. meet 答案 B. 39。m sorry to keep you waiting. Oh, not at all. I ___ here only a few . have beenB. had beenC. wasD. will be