One Riddle, One Answer, Suffixes

1. careful
2. cheerful
3. helpful
4. colorful
5. harmful
6. peaceful
7. pitiful
8. painless
9. priceless
10. helpless
11. sleepless
12. rainless
13. helplessly
14. carefully
15. peacefully
16. doctor
17. dollar
18. December
19. wonderful
20. cloudless