Asked: simple past. Had asked: Past perfect. I asked him to go out with me. This time he accepted. I had asked him two years ago, but he had refused at that time.

Hello! I agree - "I asked him" is simple past tense which means it was a simple action done in the past. and "I had asked him" is past perfect tense which means that it started in the past - we don't know how long it went on for and then it ended in the past as well. This is used more to indicate things that have happened in the past and at different times in the past. I hope that helps!

I asked him → simple past tense I had asked him → past perfect tense past perfect tense is used to express an action which was taken before an action in the past ! For example: I had watched TV before I went to the store yesterday. It means that yesterday, for example I watched TV at 3:00 PM and after that I went to the store at 6:00 PM I had learned English before I learned French. It means that at first, I learned English and after that, I learned French and both of them happened in the past. I hope this was useful :)