Prefix "un-"
* Happy - Unhappy
* Lucky - Unlucky
* Tied - Untied
* Real - Unreal
* Important - Unimportant
* Able - Unable
* Safe - Unsafe
* Conscious - Unconscious
* Certain - Uncertain
* Natural - Unnatural
Prefix "in-"
* Correct - Incorrect
* Active - Inactive
* Complete - Incomplete
* Efficient - Inefficient
* Formal - Informal
* Visible - Invisible
* Sane - Insane
* Secure - Insecure
* Valid - Invalid
* Tolerant - Intolerant
Prefix "dis-"
* Agree - Disagree
* Connect - Disconnect
* Appear - Disappear
* Honest - Dishonest
* Trust - Distrust
* Approve - Disapprove
* Like - Dislike
* Orderly - Disorderly
* Respect - Disrespect
* Able - Disable
Prefix "im-"
* Possible - Impossible
* Perfect - Imperfect
* Patient - Impatient
* Mature - Immature
* Partial - Impartial
* Moral - Immoral
* Proper - Improper
* Mortal - Immortal
* Practical - Impractical
* Pure - Impure
Prefix "mis-"
* Understand - Misunderstand
* Behave - Misbehave
* Judge - Misjudge
* Use - Misuse
* Lead - Mislead
* Inform - Misinform
* Translate - Mistranslate
* Quote - Misquote
* Calculate - Miscalculate
* Represent - Misrepresent
These are just a few examples, and there are many other prefixes that can be used to create antonyms. It's important to note that not all words with prefixes have opposite meanings. Some prefixes can change the meaning of a word in a more subtle way, and some words may have multiple antonyms.