1. I've lived here since 1999. 2. He's worked there since May. 3. They've been friends since they started college. 4. We've known him for three years. 5. They've lived in our house for two years. 6. She's been ill since Friday. 7. I haven't been in London since I was a child. 8. I've left Kyiv last year and I haven't seen him since. 9. He's studied French for ten years. 10. My mother has worked in the factory for some years. 11. They've lived in Brazil since 1960. 12. I haven't seen him since this Tuesday. 13. He's been in prison now for five years. 14. She hasn't heard about them for almost a year. 15. I've known nothing about him for several times.