Give the opposites important- popular- active- pleasant- necessary- formal- natural- different- done-

Important- unimportant
Popular- unpopular
Active-inactive
Pleasant- unpleasant
Necessary-unnecessary
Formal-informal
Natural- Unnatural
Different- indifferent
Done-undone

Opposites: (просто добавлять в начале in/un)

1. Important - unimportant
2. Popular - unpopular
3. Active - inactive
4. Pleasant - unpleasant
5. Necessary - unnecessary
6. Formal - informal
7. Natural - unnatural
8. Different - indifferent
9. Done - undone