Prefix to form opposite meaning

☄ Equal – Unequal

☄ Certain – Uncertain

☄ Kind – Unkind

☄ Real – Unreal

☄ Limited – Unlimited

☄ Lawful – Unlawful

☄ Usual – Unusual

☄ Happy – Unhappy

☄ Do – Undo

☄ Load – Unload