We can use it to refer to an action that has finished but you can still see evidence.
- Oh, the kitchen is a mess. Who has been cooking?
- You look tired. Have you been sleeping properly?
- I’ve got a a stiff neck. I’ve been working too long on computer.
It can refer to an action that has not finished.
- I’ve been learning Spanish for 20 years and I still don’t know very much.
- I’ve been waiting for him for 30 minutes and he still hasn’t arrived.
- He’s been telling me about it for days. I wish he would stop.
It can refer to a series of actions.
- She’s been writing to her regularly for a couple of years.
- He’s been phoning me all week for an answer.
- The university has been sending students here for over twenty years to do work experience.
- I’ve been wanting to do that for ten years.
- You haven’t been getting good results over the last few months.
- They haven’t been working all week. They’re on strike
- He hasn’t been talking to me for weeks.
- We’ve been working hard on it for ages.
- I’ve been looking at other options recently.
- He’s been working here since 2001.