present perfect...

We normally use the present perfect when we are thinking abaut past evens together with their present results.

Positive form:
we put Have in (I,You,We and They) and Has in (He,She and It).
regulars verbs:we put -ed, play-played.
ex: Se has played basketball.

irregulars verbs: we use the participle verbs,swim,swam,swum.
ex:Yu have swum in the pool.


Negative form:
we put have not in (I,You,We and They) and Has not in (He,She and It) and the participle verbs.
ex: You haven't swum in the pool.
She hasn't played basketball.


Interrogative form:
we use Have or Has subjet and the verb in participle.
ex: Have you swum in the pool?
Has she played basketball?


in this tense we can use:
have you ever...? or Has she ever....?, How long...?, just, since or for.