The Rules of Present Perfect Grammar

Present perfect is a tense used to talk about an action in the past that has some kind of result now in the present. The sentence I always like to use is I have opened the door. In the past, I opened the door and it's still open now. So don't worry. If we use past simple, I opening the door. This is just a simple past action. And it kind of means now maybe it's open. Maybe it's not. Some of them are a bit harder, especially like go went gone. Am or B was and bean. They can get a little bit different but they're really, really useful.