1. Able - unable
2. Active- inactive
3. Believable-unbelievable
4. Capable- uncapable
5. Certain-uncertain
6. Comfortable-uncomfortable
7. Fashionable-unfashionable
8. Formal-informal
9.happy-unhappy
10. Perfect-imperfect
11. Polite-impolite
12. Possible-impossible
13. Sure-unsure