4 現(xiàn)在完成時(shí)和一般過(guò)去時(shí)的區(qū)別

現(xiàn)在完成時(shí)和一般過(guò)去時(shí)都表示在過(guò)去完成的動(dòng)作。但現(xiàn)在完成時(shí)強(qiáng)調(diào)的是這一動(dòng)作與現(xiàn)在的關(guān)系。如對(duì)現(xiàn)在產(chǎn)生的結(jié)果或影響等,而一般過(guò)去時(shí)只表示動(dòng)作在過(guò)去某一時(shí)刻發(fā)生,不表示和現(xiàn)在的關(guān)系。試比較:

I have lost my new book. 我把新書(shū)丟了。(現(xiàn)在還未找到)

I lost my new book yesterday. 我昨天把新書(shū)丟了。(昨天丟的,現(xiàn)在找到與否沒(méi)說(shuō)明)

The light has gone out.燈已經(jīng)息了.(現(xiàn)在尚未亮)

The light gone went out.燈曾經(jīng)息過(guò).(現(xiàn)在已亮了)

5 幾點(diǎn)注意事項(xiàng)

I.? have been(to)與have gone( to)的區(qū)別:

have been(to)表示“去過(guò)某地(現(xiàn)在已經(jīng)回來(lái)了)”,可用于各人稱;have gone(to)表示“去某地了(說(shuō)話時(shí)某人不在當(dāng)?shù)兀?,常用于第三人稱,前者可與once ,never,several times等連用,后者則不能。如:

They have been to Beijing twice.他們?nèi)ミ^(guò)北京兩次。

He has gone to Beijing . 他去北京了。

II. 如單純表示一段時(shí)間,或強(qiáng)調(diào)一段時(shí)間,雖有since一詞,也不必用完成時(shí)。如:

It is two years since his father died. =His father has been dead for two years.他父親去世已有三年了。
 
Ⅲ. 不可延續(xù)性動(dòng)詞現(xiàn)在完成時(shí)的否定式,已變成一種可以延續(xù)的狀態(tài),因此可以和表示一段時(shí)間的狀語(yǔ)連用。如:

I haven't left here since 1997.自從1997年以來(lái),我一直沒(méi)有離開(kāi)過(guò)這兒。

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

(對(duì))I haven't received his letter for almost a month.
 
6 用于現(xiàn)在完成時(shí)的句型
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.

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。