The perfect aspect

in the present:
Ex. I’ve painted the room. (my walls in the room are blue now)
use for unfinished actions that has continued up to the “now” moment:
Ex. I have known Jack for 5 years now.
use with the time espressions: already, yet, just, recently, for, since, ever/never.
Ex. I haven’t called her yet.
She has had her car for 3 years already.
use with stative verbs: know, have, be, see and etc.