Present Perfect = Something started in the past but it still continues, or you talk about the result.
It has rained. The streets are still wet. (you talk about the result)
He has played with this band since 1990. (since -> so it still continues)
They have always worked there. (always-> so it still continues)
You do this by putting have/has in front of the verb and add –ed at the end of the verb. Signal words: for, since, just, yet, ever, never, how long, already, always.
IRREGULAR VERBS: have/has + 3rd word! (fly-flew-flown)
IRREGULAR VERBS: 2nd word! (fly-flew-flown)