Present perfect vs Present perfect continuous 

We use both of these tenses for finished and unfinished actions.

The present perfect simple can be used (with 'since' and 'for') to talk about unfinished actions that started in the past and are still happening in the present. It's often used with stative verbs: I've known Martha for three years.

The present perfect continuous can also be used (with 'since' and 'for') to talk about unfinished actions that started in the past and are still happening in the present. (We don't use the present perfect continuous with stative verbs): She's been living here for three years.

Sometimes there's really no difference in meaning between the two tenses. Especially  with verbs as 'live', 'work' and 'study':

• They've lived in London since 2004.
• They've been living in London since 2004.

Sometimes, there is a difference in meaning:

The present perfect continuous can be used to emphasise the length of time that has passed. The present perfect simple is generally neutral:

• They've been waiting for hours! (This emphasises the length of time).
• They've waited for hours. (This doesn't emphasise the length of time).

The present perfect simple is often used when we're talking about how much or how many. This is NOT possible with the present perfect continuous:

• She's drunk three cups of coffee this morning
• (NOT: she's been drinking three cups of coffee this morning).

We use 'yet' and 'already' with the present perfect simple:

• Have you read the book yet?
• She's finished her work already.

This difference is often used to talk about different kinds of results in the present. The present perfect simple is used when the action is finished, and the result comes from the action being finished:

• I've eaten dinner, so let's go out.
• She's done all her homework, so she can relax this evening.
• I've made a cake. Would you like some?

The present perfect continuous is used when the result comes from the action itself. It doesn't matter if the whole action is finished or not. The result is often something we can see, hear, smell, or feel:

• I've been eating dinner, so there are plates all over the table.
• She's been doing her homework, so she's tired.
• I've been making a cake, that's why the kitchen is such a mess.

EXEMPLE

What does Diana think of your idea?

I don't know. She hasn't answered my message yet.

Are Saul and Lily a couple?

No, they are just friends . They have known each other for years.

Hey, how did he get so good at football?

He has been playing with his brothers all his life!

Do you and Juliet feel like going to that new action film?

No, thanks. We have already seen it.

Why don't you answer the phone?

Sorry. It has been on silent since last night.

Why are you going to bed so early?

Because I am tired . I have been working on this project for hours.