現(xiàn)在完成時的結(jié)構(gòu)課件

　　現(xiàn)在完成時的結(jié)構(gòu)課件

　　由“have/has+過去分詞”構(gòu)成，主要有兩個含義： ①表示動作發(fā)生在過去，但與現(xiàn)在的情況有聯(lián)系，有時無時間狀語，有時和一些表示不確定的過去時間狀語連用，如：many times，just，yet，ever，never，already，before，so far, by now等連用。 ②表示從過去某一時間開始一直延續(xù)到現(xiàn)在并還可能繼續(xù)延續(xù)下去的動作，用于延續(xù)性動詞，且句中常帶有表示一段時間的時間狀語，如：for two months, so far等。

　　時態(tài)結(jié)構(gòu)

　　現(xiàn)在完成時由“have/has+過去分詞”構(gòu)成，主要有兩個含義：

　　①表示動作發(fā)生在過去，對現(xiàn)在有影響，有時無時間狀語，有時和一些表示不確定的過去時間狀語連用，如：many times，just，yet，ever，never，already，before，so far, by now等連用。

　　②表示從過去某一時間開始一直延續(xù)到現(xiàn)在并還可能繼續(xù)延續(xù)下去的動作，用于延續(xù)性動詞，且句中常帶有表示一段時間的時間狀語，如：since + 時間點/從句，for two months, so far等。[1]

　　在“it is the first/second...time that...。”或在“it/this/that is the +最高級+名詞+that...。”結(jié)構(gòu)中，that從句中的動詞常用現(xiàn)在完成時；表示到說話時為止動作發(fā)生過幾次。在“it + be...+since從句”這一結(jié)構(gòu)中，be可用一般現(xiàn)在時或現(xiàn)在完成時，since從句一般用過去時。have/has/had +been +動詞的現(xiàn)在進(jìn)行時。

　　1）現(xiàn)在完成時和一般過去時都能表示過去發(fā)生過的動作，但現(xiàn)在完成時表示過去動作對現(xiàn)在的影響，并且表示這一動作已完成或還可能繼續(xù)下去；

　　2）而一般過去時與現(xiàn)在的情況沒有聯(lián)系，僅表示過去的動作，且這一動作到說話時已終止。因此現(xiàn)在完成時不能與表示明確的'過去時間如：in1949，yesterday，last week等的狀語連用，并且用when或where對這些時間和地點狀語提問時，一般只用一般過去時。

　　比較過去時與現(xiàn)在完成時

　　1）過去時表示過去某時發(fā)生的動作或單純敘述過去的事情，強(qiáng)調(diào)動作；現(xiàn)在完成時為過去發(fā)生的，強(qiáng)調(diào)過去的事情對現(xiàn)在的影響，強(qiáng)調(diào)的是result (結(jié)果）。

　　2）過去時常與具體的時間狀語連用，而現(xiàn)在完成時通常與模糊的時間狀語連用，或無時間狀語。一般過去時的時間狀語:

　　yesterday, last week，…ago, in1980, just now, 具體的時間狀語

　　共同的時間狀語:

　　this morning, tonight, this April, now, once，before, already, recently，lately

　　現(xiàn)在完成時的時間狀語

　　for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,

　　不確定的時間狀語

　　3）現(xiàn)在完成時可表示持續(xù)到現(xiàn)在的動作或狀態(tài)，動詞一般是延續(xù)性，如live, teach, learn, work, study, know.

　　過去時常用的非持續(xù)性動詞有come, go, leave, start, die, finish, become, get married等。

　　舉例：

　　I saw this film yesterday.

　　（強(qiáng)調(diào)看的動作發(fā)生過了。）

　　I have seen this film.

　　（強(qiáng)調(diào)對現(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)起床的動作已發(fā)生過了。）

　　Who hasn't handed in his paper?

　　（強(qiáng)調(diào)有卷子，可能為不公平競爭。）

　　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?

　　---He's already been sent for.

　　句子中如有過去時的時間副詞（如 yesterday, last, week, in 1960）時，不能使用現(xiàn)在完成時，要用過去時。

　　（錯）Tom has written a letter to his parents last night.

　　（對）Tom wrote a letter to his parents last night.

　　用于現(xiàn)在完成時的句型

　　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。

　　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.

　　This is the best film that I've (ever) seen.

　　這是我看過的最好的電影。

　　This is the first time (that) I've heard him sing.這是我第一次聽他唱歌。

　　典型例題

　　---No, this is the first time I ___ here.

　　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，故選B。

　　---No, it's the first time I ___ here.

　　even, come B. even, have come C. ever, come D. ever, have come

　　答案D. ever意為曾經(jīng)或無論何時，反意詞為never，此兩詞常用于完成時。 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。

　　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。

　　（錯）I have received his letter for a month.

　　（對）I haven't received his letter for almost a month.

　　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.

　　(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+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。

　　(對) Tom has studied Russian for three years.

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

　　(錯) 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.