1. The last time I saw John was when he was leaving for Edinburgh
- I haven't seen John since he left for Edinburgh
2. They haven't liked ice-cream since they ate too much and were sick
- They didn't like ice-cream after they ate too much and were sick.
3. John began working as a television presenter 5 years ago
- John has been working as a television presenter for 5 years.
4. My uncle has been a worker in that factory for 10 years
- My uncle started working in that factory 10 years ago.