since
in (negatives)
for
They've been out three or four times.
PERIODS OF TIME
PRESENT PERFECT
What have you been doing lately?
results / how many times
POINTS IN TIME
PRESENT PERFECT CONTINUOUS
Who has she been seeing?
ongoing / repeated activities
What things have you made so far?
How many times have they gone out together?
I've made eight vases and two bowls.
I've been going to a pottery class.
She's been seeing a guy from work.
