Q: Is the apartment ready?
A: Yes, I have painted it. (Result= the rooms are now painted.)
Q: Can Jerry ride his bike to the park?
A: Yes, Jerry has fixed it. (Result = he can ride it now.)
Q: Why do you have paint in your hair?
A: I have been painting the apartment.
(Recent or partially complete extended activity=painting the apartment)
Q: Why are Jerry's hands so dirty?
A: He has been fixing his bike.
(Recent or partially complete extended activity=fixing his bike)