Update: I'm not looking for an explanation to the two specific sentences below. I'm looking for a learning resource which gathers examples in the form presented.
The English “perfect” is deeply puzzling for learners
As a non-native speaker on the C1/C2 level, I can't stress how annoying it to put so much effort into trying to understand it, yet still making mistakes - I think mainly because this tense doesn't exist at all in my native language (Polish).
What I'm looking for, and I couldn't find it anywhere, is a website or a book that gives two sentences with the only difference being past simple or present perfect - then explains in details what is the difference in meaning and in what context one would be preferred over the other:
1a. Thanks, I've had a great time.
1b. Thanks, I had a great time.
Usage: Sentence 1a would be used in situations like .... Sentence 1b would be used in situations like ..., because of ....
Just that. The more examples, the better. Is there anything out there?