在表达一个在过去开始而现在仍在继续或刚刚结束的动作时,某些动词既可以用现在完成时,也可以用现在完成进行时。这样的动词有expect,hope,learn,lie,live,look,rain,sleep,sit,snow,stand,stay,study,teach,wait,want,work等.
How long have you learnt English?你学习英语多久了?
How long have you been learning English?(译文同上。)
He has slept for ten hours.他已经睡了十个小时了。
He has been sleeping for ten hours.(译文同上。)
It has snowed for a long time.雪下了好长时间了。
It has been snowing for a long time.(译文同上。)

没有进行式的动词不可能有这样的用法,即现在完成进行时不能代替以下例句中的现在完成时:
They’ve always had a big garden.他们一直有一座大花园。
How long have you known that?你知道这事多久了?
He’s been in hospital since his accident.他从发生事故之后,一直在医院里。

注意:现在完成进行时可以和时间短语连用,也可以不连用,这一点就有别于现在完成时,因为后者与像for six days,since June,never等一些时间短语连用才能表示这类动作。不用这些时间状语时,现在完成时指的是完成了的一个动作。

B 用现在完成时表示的反复的动作,有时可以作为连续的动作用现在完成进行时表示:
I’ve written six letters since breakfast.早饭后我已经写了六封信。
I’ve been writing letters since breakfast.早饭后我一直在写信。
I have knocked five times.I don’t think anyone’s in.
我敲了五次门。我想屋里没有人。
I’ve been knocking.I don’t think anybody’s in.

我一直在敲门。我想屋里没有人。
注意:现在完成进行时表示一种看来似乎是不间断的动作,所以提到做一件事的次数或一共做了多少事情时,不能用现在完成进行时。

C 用现在完成时表达的单一动作和用现在完成进行时表达的动作是有区别的:
(a)I’ve polished the car.我擦了车。意指这件事已经结束了。
(b) I’ve been polishing the car.我在擦车来着。

意指过去一小时我就是这样度过的,而不一定指动作已结束。注意:用现在完成进行时表示单一动作时,这一动作持续到说话的时间或者接近这一时间为止:
He’s been taking photos.
他一直在拍照。(他大概手里正拿着照相机。)
He has taken photos.
他拍过相片。(这件事可能是也可能不是最近发生的。)

例句:

1.He has been speaking English since he came to the USA.
(现在完成进行时,强调动作的连续性。

2.Complete these sentences with the present continuous form of the verbs given in the brackets, changing the word order where necessary.
用括号中所给的动词的现在进行时完成句子,必要时变化词序。

t perfect ph.1. 【语】现在完成时,2. 【语】现在完成时的

4.During the procession, the microprocessor finished the processing procedure.
在队伍行进时,微处理器完成了加工过程.

execute and complete certain Works and remedy any defects therein as therein mentioned in conformity with the provisions of the said Contract.
去实施并完成某项工程,并在工程出现任何缺陷时,按上述合同中有关条款规定进行修补。

6.Installation of applications on this computer is complete. The computer will now restart.
已完成在此计算机上进行的应用程序安装。计算机现在要重新启动。

7.During Iteration Planning, the Customer presents the features desired for the next two weeks.
在进行迭代计划时,客户演示下两周内希望完成的特性。

8.Change the following sentences into the Present Continuous Passive Voice.
把下列句子变成现在进行时的被动语态。

9.`I have finished' is an example of the present perfect.
“我已经完成了”是现在完成时态的一个例句。

10.a perfective tense used to express action completed in the present.
一种用来表达现在已经完成的动作的完成时态。

11.And will learn The simple past tense, The present perfect tense, The past perfect tense as well as The future tense.
这个学期,我们学到了过去时,现在完成时,过去完成时和将来时等。

12.Cleanup of merge meta data cannot be performed while merge processes are running. Retry this operation after the merge processes have completed.
合并进程运行时无法执行合并元数据的清除。请在合并进程完成后重试此操作。

13.Download Complete. Extracting Files.
下载完成。正在对文件进行解压缩。

14.The work is in hand and will soon be completed.
这工作在进行中, 不久即可完成.

15.The work is in hand and will soon be finished .
工作在进行中,很快就会完成。

16.The work be In hand and will soon be completed
这工作在进行中, 不久即可完成

17.The request has been accepted for processing, but the processing has not been completed.
已接受请求,正在进行处理,但尚未完成。

18.Queen Mary's joint degrees will be taught entirely in China.
女王玛莉双学位将完成在中国进行。