Past simple vs. present perfect

I lived there last year. Present perfect, Simple. I've lived there before. Doesn't matter when. It matters that I know the place. I've lived there. I lived. I've lived. I lived. I've lived. I worked yesterday. What did you do yesterday? I worked. I worked yesterday. I've worked in that company. Yesterday, Last year, last month. Doesn't matter. What matters is the fact that I have the experience of working in that company. I have an entire mini training called the Grammar Master. And there I have 10 lessons about each tense where I explain the tense in a very simple and efficient way. I explain the pronunciation, and we practice drills of different sentences and different structures so that you can internalize the tense and start using it more automatically and naturally.