More on present perfect

Some weeks ago we studied the present perfect with students in class III D. We enjoyed making a speaking activity on it and I wrote this post with some useful links.
As we reviewed it this morning and added more information here is a page to remind you how to form the present perfect and when to use it.

PRESENT PERFECT: USE

1) Result of an action in the past that is important in the present

I have cleaned my room.

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2) Recently completed action

He has just played handball.

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3) State beginning in the past and still continuing

We have lived in Canada since 1986.

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With this words

just, yet, never, already, ever, so far, up to now, recently, since, for

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FORM

have/has + past participle

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Examples

Affirmative sentences:

I have cleaned my room. I've cleaned my room.

You have cleaned your room. You've cleaned your room.

Negative sentences:

I have not cleaned my room. I've not cleaned my room. I haven't cleaned my room.

You have not cleaned your room. You've not cleaned your room. You haven't cleaned your room.

Questions:

Have I cleaned my room?

Have you cleaned your room?

Here are some new exercises on since and for. 
http://www.englishexercises.org/makeagame/viewgame.asp?id=1394



And here other exercises to practice this structure.
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises