explaining present perfect

How can I explain the present perfect tense? It is difficult for someone who doesn't use it in his language!

well that may be the truth 'cause in different cultures they have different grammer structure.

it can be explained by only giving more examples,,conversations so they can get used to it…

hmmm i would ask my students to give examples..

That's really hard. It was hard to me, too. Furthurmore, you use it slight differently than British. A bit rarer. I mean: Br: I've opened the door. would be US: I opened the door. Though it's still open.

Feri