1. Would you like to be able to retire before you're 55, or do you think you'd get bored?
2. I've tried all the shops in the city, but I haven't been able to find a bicycle that I really like.
3. In spite of ordering far too much food, my mother-in-law was able to/could finish all of it and ask for a dessert!
4. We're fully booked this weekend, but we can/could/will be able to come round for dinner the weekend after.
5. Pepito loves being able to go on holiday whenever he feels like it.