Present Perfect Progressive
The simple present perfect is already a complex tense form. But for the English this doesn't seem to be enough. They won't stop
before their verb forms are nothing less than a procession of obedient auxiliaries supporting a royal full verb. And here it comes, the
As always, the progressive form describes the action as a running process. Because present perfect always concentrates on a
time period from some point in the past to the present, its progressive form is used in exactly one situation:
An action started in the past and is still running at the moment of speaking.
Please note this important difference compared to the simple form, which concentrates either on a state or a result.
Basically, this is a combination of the rules for simple present perfect and present progressive.
Watch the video for details.
They have been waiting for me since three o'clock.
We had an appointment and I am probably very late by now.
I have been going to this school for eight years.
The speaker started attending this school eight years ago and is still a student here.
Note the difference to the past tense version I went to this school for eight years.
In this case the speaker has already left this school. This could be only a moment or even several years in the past.
At the moment of speaking the subject could be anything between a teenager and an old-age pensioner.
Since and For
These words in combination with a phrase of time usually appear together with present perfect, both simple and progressive.
They are almost guaranteed to cause problems for the language learner. However, there is a simple
rule of thumb to avoid such mistakes. Have a look at the following two sentences:
He has been trying to understand English tense forms for many years.
His class mate has been a happy person since she stopped trying.
Most grammar books tell you that one sentencen describes a period of time and the other one speaks about a point of time.
This is not entirely true because most present perfect sentences refer to a period of time.
I haven't seen you since Thursday. and I haven't seen you for three days. both refer to a period of time of several days.
The correct way to think about it is What graphical symbol would I use to draw the adverbial phrase of time
in a time line?
If you'd draw it as a bracket, you must use for. This describes a period of time.
I've been learning English for 20 years now.
Get up, the alarm clock has been sounding for two minutes.
This hasn't changed for years.
If you'd draw it as a point, you must use since.
This describes a moment in time (no matter how long this moment is).
I've been learning English since 1997 now.
Get up, the alarm clock has been sounding since 6 o'clock.
This hasn't changed since the beginning of time.
A final warning: The last sentence above is a good example of where the trap lies. Don't think about drawing on your time line
since the beginning of time. This will always be a bracket. Try to draw the beginning of time instead.
You will agree that this must be a point.