Hallo, everyone! It's almost a year I'm user of this forum but I still have been feeling that I don't feel the difference between «did something» and «have done something» (I mean Simple and Perfect past tenses). In books of course I saw explanations that Perfect is used without additional information (time of action) and Simple is used with it. For example «Yesterday I wrote a book» and «Yes! I have written it!». But while reading English texts sometimes I don't see that authors follow these rules. I meet sentences like «Did you see the movie?» or «Yesterday John Petrov has visited public toilet». It confuses me a lot. Would somebody explain it for me? What are these situations when I may use any rule I want and when do I use only one of them? Thanks.