Present perfect continuous

The present perfect continuous is used to talk about activities that started in the past and are unfinished.

We've been rehearsing “The Rite of Spring” recently for a concert.
I think she's just tired because she's been working so hard.

for and since

For is used to give an amount of time.

I've been playing the trumpet for ten years now.
For the last few weeks, they've been showing a series on TV based on the books.

Since is used to say when the period of time started.

I've been learning Turkish since 2012.
I've been playing the violin since I was about twelve.
We met at school and we've been good friends since then.

Verbs not in present perfect continuous

Some verbs are generally used in the present perfect simple — not the present perfect continuous, e.g.

be, believe, hate, like, know.

Look at

I've liked her ever since then.
I've known I wanted to be an artist since I was three.

We use present perfect continuous to talk about how long - and to focus on the activity.

We use the present perfect simple to talk about how many - and to focus on finished achievements in the timpe up till now.

I've been phoning him all morning, but he's not anwering. (=how long)
I've phoned ten shops, but none of them had the book! (=how many)

They've been meeting since April to discuss the project. (=how long)
We've met several times beofre. (=how many)