action which started in the past and continues up
to the present.She has been preparing for her exams since Monday.
for an action which started in the past and lasted for some time. It may still be continuing, or have finished, but it has left a visible result in the present.
He is tired because he has been dancing all night long.
to express anger, irritation or annoyance / criticism.
She has been using my computer without asking me.
for repeated actions in the past continuing to the present
He has put on the weight because he has been eating junk food every day since last month
PRESENT PERFECT CONTINUOUS
Time expressions
since
for
how long
just
already
yet
ever
never