Present perfect simple or continuous

Often there is very little difference between the present perfect simple and the present perfect continuous. In many cases, both are equally acceptable.

• They've been working here for a long time but Andy has worked here for even longer.
• I've lived here for 10 years and she has been living here for 12 years.

To emphasize the action, we use the continuous form.

• We've been working really hard for a couple of months.
• She's been having a hard time.

To emphasize the result of the action, we use the simple form.

• I've made fifteen phone calls this morning.
• He's written a very good report.

Look at the difference in these examples.

• I've been reading this book for two months but I've only read half of it. It's very difficult to read.
• She's been trying to convince him for 20 minutes but she hasn't managed to yet.
• They've been talking about this for month and they still haven't found a solution.

When an action is finished and you can see the results, use the continuous form.

• The phone bill is enormous. You've been calling your boyfriend in Australia, haven't you?
• You're red in the face. Have you been running?

When you use the words 'ever' or 'never', use the simple form.

• I don't know them. I've never met them.
• Have you ever heard anything so strange in your life.