present perfect

Present Perfect - Use

1) Result of an action in the past is important in the present
I have cleaned my room.
2) Recently completed action
He has just played handball.
3) Action beginning in the past and still continuing
We have lived in Canada since 1986.
4) together with lately, recently, yet
I have been to London recently.

Signal words
just, yet, never, already, ever, so far, up to now, recently, since, for
Form
have/has + past participle