用于現(xiàn)在完成時(shí)的句型

6. 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 I’ve (ever) seen.  
　　　 這是我看過(guò)的最好的電影。 
　 This is the first time (that) I’ve heard him sing.　這是我第一次聽(tīng)他唱歌。 

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 coming  
　 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。 

(2) ---Have you ____ been to our town before? 
　 ---No, it’s the first time I ___ here. 
A. even, come　 B. even, have come　　C. ever, come　 D. ever, have come 
　 答案D. ever意為曾經(jīng)或無(wú)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 +that-clause 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(yǔ)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 haven’t received his letter for almost a month. 
12. 比較since和for 

　　Since 用來(lái)說(shuō)明動(dòng)作起始時(shí)間，for用來(lái)說(shuō)明動(dòng)作延續(xù)時(shí)間長(zhǎng)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(yǔ)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(mén)：　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 ago.　或 Harry has been married for six years. 
13. since的四種用法 

　 1) since +過(guò)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.