The present perfect progressive expresses the meaning “until now” and makes the connection between the past and present. Since it is progressive, it usually connotes an idea of continuity. It is often used with prepositional phrases: for + amount of time and since + point in time.
I have been living in Minneapolis since 1999.
I have been living in Minneapolis for three years.
The present perfect progressive tense is made by placing have been (or has been) immediately in front of the –ing form of the main verb.
The present perfect progressive can sometimes be interchanged with the present perfect tense with little or no deviation in meaning.
Esther has worked there for nine years.
Esther has been working there for nine years.
However, in cases where the present perfect tense carries the meaning “before now” (non-specific time in the past), the present perfect progressive cannot be used.