1. I used to do that before
2. I used to believe in Santa Claus
3. I used to eat a lot of sweets
4. I used to smoke a lot
5. I used to sing with my friend
6. I used to play guitar
7. I used to play with my sister
8. I used to go to the theatre
9. I used to be mad at you
10. I used to walk with my dog
11. I used to watch cartoons
12. I used to do my homework
13. I used to read a book
14. My mom used to work a lot
15. I used to go to school today