Для перевода предложений в косвенную речь, мы меняем время глаголов, местоимения и наречия времени/места, если это необходимо. В данном случае, все предложения начинаются с "Nick said that...".
Ответ: 1. Nick said that he had lived in Berlin many years ago. 2. Nick said that his mother was at home. 3. Nick said that he knew what Tom was doing. 4. Nick said that I couldn't stay at his place. 5. Nick said that they were not enjoying the study very much. 6. Nick said that I had sent him a fantastic card. 7. Nick said that the children had been glad to get a cat. 8. Nick said that the new play would be fantastic. 9. Nick said that they went to bed late on Saturday. 10. Nick said that I had bought the new game.