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。

　　2017 昆明小升初家長群 106422652

　　2017 昆明小升初家長群 106422652

　　注意：非延續(xù)性動詞的否定形式可以與表示延續(xù)時間的狀語連用。即動作不發(fā)生的狀態(tài)是

　　可以持續(xù)的。

　　I have received his letter for a month.

　　I haven t received his letter for almost a month.

　　3  比較since和for

　　Since 用來說明動作起始時間，for用來說明動作延續(xù)時間長度。

　　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 作為時間狀語的句子都用現(xiàn)在完成時。

　　I worked here for more than twenty years.

　　I have worked here for many years.

　　小竅門： 當(dāng)現(xiàn)在完成時+一段時間，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)動詞在完成時中的誤使。

　　2017 昆明小升初家長群 106422652

　　2017 昆明小升初家長群 106422652

　　1) Tom has studied Russian for three years.

　　= Tom began to study Russian three years ago, and is still studying it now.

　　2) 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，它應(yīng)改為 Harry got married six years ago. 或 Harry has been

　　married for six years.

　　4  since的四種用法

　　1) since +過去一個時間點(diǎn) 。

　　I have been here since 1989.

　　2) since +一段時間+ 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 +一段時間+ since從句

　　It is two years since I became a postgraduate student.

　　5 延續(xù)動詞與瞬間動詞

　　2017 昆明小升初家長群 106422652

　　2017 昆明小升初家長群 106422652

　　1) 用于完成時的區(qū)別

　　延續(xù)動詞表示經(jīng)驗(yàn)、經(jīng)歷; 瞬間動詞表示行為的結(jié) 果，不能與表示段的時間狀

　　語連用。

　　He has completed the work. 他已完成了那項(xiàng)工作。

　　I ve known him since then. 我從那時起就認(rèn)識他了。

　　2) 用于 till / until 從句的差異

　　延續(xù)動詞用于肯定句，表示 做 直到 瞬間動詞用于否定句，表示 到 ，才

　　He didn t come back until ten o clock.

　　他到 10 點(diǎn)才回來。

　　He slept until ten o clock.

　　他一直睡到 10 點(diǎn)。

　　典型例題

　　1. You don t need to describe her. I ___ her several times.

　　A. had met B. have met C. met D. meet

　　答案 B. 首先本題后句強(qiáng)調(diào)對現(xiàn)在的影響，我知道她的模樣，你不用描述。再次，

　　several times 告知為反復(fù)發(fā)生的動作，因此用現(xiàn)在完成時。

　　2.---I m sorry to keep you waiting.

　　---Oh, not at all. I ___ here only a few minutes.