1. When the water boils, remove the kettle and brew tea. 2. Will the cat run away if we release it? 3. If you write the address on the envelope, I will send a letter. 4. We will go to Zagorsk on Sunday only if the weather is good. 5. I will never believe it until I see her with my own eyes. 6. We will start learning French when we enter our second year. 7. As soon as the guests leave, I will sit down to work again and work until three in the morning. 8. He will not go out until the doctor allows him to walk. 9. I want to do all the exercises before you pick up the textbook. 10. Anna will clean the room while Maria prepares dinner. 11. If you get tickets for the premiere, you will let me know, right? 12. Harry will take the magazines to the library as soon as he looks through them. 13. Don't wait for me if I'm late. Before I come to the meeting of the group, I will go to the dean's office and get the necessary papers. 14. John will not start writing a new article until he finishes the first and shows it to his supervisor. 15. We will not discuss the film in English class before all the students have watched it. 16. Turn off the radio and lights before leaving (before you leave home). 17. The secretary will print these letters after the director approves them. 18. We will study in the reading room until it closes. 19. He will never give a report if he does not receive all the data at least a week in advance. 20. If you feel like having a good laugh, go see this movie. 21. Whenever he comes home, ask him to call me. 22. If you don't water your flowers regularly, they will wither. 23. If you don't forget, please buy me a couple of envelopes at the post office. 24. What will I tell him if he comes while you are not at home?
ты употребляешь Present Perfect когда у тебя есть такие показатели времени: since, yer, for и другие(можешь почитать в интернете) если у тебя есть такие слова, то скорее всего это будет Present Perfect
Past Simple ты употребляешь когда есть слова last (last week, last weekend и тд) yesterday и ещё парочка (можешь посмотреть в интернете)