hi ,
i have some sentence i hope to find explications answar me quation "why we use the presnt perfect or present perfect continuous ?? "

1. Tom's has got an important job to finish by the end of the month. He (stay) at work until after 10 o'clock three days this week already.
2. Marie has been in Stockholm for a few weeks now. She (stay) with her friend Inga while she's there.
3. I (see) a physiotherapist for a couple of years- ever since I broke my wrist.
4. We reached the top of hill as the sun began to disappear beneath the horizon. It was one of the most spectacular sunsets I (see) in my whole life.
5. A) where have you been all day? B) I (finish) my homework.
6. A) you are looking pleased with yourself. B) Yes, (finish) my last exam and I'm going on holiday tomorrow.
7. A) Do you fancy a game of squash this week end?B) No thanks. I (play) a couple of times before, but I just can't get the hang of it.
8. A) Paul! Look at your clothes! B) Sorry Mum. I (play) football in the park and it was a bit muddy.
and thanks befor

Is the action something that extends continuously, habitually, or regularly from the past to the present?  That is, at any point in time between the start of the action and now, if you looked at what was happening, would this action be happening?  If so, you need the continuous tense.  Otherwise, don't use the continuous tense.

Look at the second example.

Marie has been in Stockholm for a few weeks now.  She ..... with her friend Inga while she's there.

Was she staying with Inga 13 days ago?  Yes.

Was she staying with Inga 12 days ago?  Yes.

Was she staying with Inga ...

Was she staying with Inga two days ago?  Yes.

Was she staying with Inga yesterday?  Yes.

It seems that the action of "staying with Inga" has been "happening" continuously.  So she has been staying with Inga while she's there. 

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Now take a look at Example 7.

I ... a couple of times before, but I just can't get the hang of it.

In my whole life I only played squash a couple of times, so that doesn't seem like a lot, does it?

Was I playing squash yesterday?  Was I playing squash the day before?  What about the day before that?  What about the day before that?  You would have to answer "Probably not" to each of these questions.

Obviously, I do not play squash regularly.  I do not play habitually.   The continuous tense does not apply.  So I have played a couple of times before.

In general, you can't use the present perfect continuous when you have done something a certain number of times.

______

Now maybe you can try them all yourself.

CJ