Often they are interchangeable. Both THE PRESENT PERFECT and THE PRESENT PERFECT CONTINUOUS talk about something which started in the past and:   either has a result in the present: He has lost his job (i.e. he’s unemployed now). I have been partying all weekend, so I’m feeling pretty tired now. or is still happening now: We have been building an extension to our house (and we haven’t finished yet) Often they are interchangeable. However:

THE PRESENT PERFECT TENSE Is used: to emphasise the result: I have phoned all my friends and they are coming to the party. to say how much you have done: I have cooked three pizzas. to give the idea that something is more permanent (and may be accompanied by a time expression which shows this): He has worked in this shop all his life. I have always lived here. when we want to say how many times something has been repeated: I have invited her two or three times but she always says she’s busy.

THE PRESENT PERFECT CONTINUOS TENSE Is used:  to emphasise the activity: I have been phoning my friends (that’s why I haven’t done my homework) to say how long you’ve been doing something: I have been cooking all afternoon.  to give the idea that something is temporary (and may be accompanied by time expression which shows this): I have been working here for the last two months until I go to the university. We have been eating dinner in the garden while the weather has been so warm.

Remember: state verbs are not normally used in the continuous! when we want to emphasise the process of change over a period of time and that these changes are not finished: Your English has been improving tremendously since you started doing your homework!   Remember: state verbs are not normally used in the continuous!