Antonym prefixes reverse the meaning of a word. English has several negative prefixes — un-, in-, im-, il-, ir-, dis-, mis-, non- — and choosing the correct one depends on the word. There are patterns, but also exceptions that must be memorised.
"Un-" is the most common negative prefix: unhappy, unusual, unwilling, unknown, unclear. "Dis-" often negates verbs and some adjectives: disagree, disappear, dishonest, disrespect, disorder. "In-" is mostly used with adjectives of Latin origin: inaccurate, incorrect, incomplete, invisible, inefficient. There is overlap — and some words accept only one prefix (no rule covers all cases).
Practice
The instructions were completely ___ — nobody knew what to do.
Sheagreed with the committee's decision.
Put the words in the correct order:
"Im-" is used before words starting with b, m, or p: impossible, imbalance, impatient, immature, imperfect. "Il-" is used before words starting with l: illegal, illogical, illiterate, illegible. "Ir-" is used before words starting with r: irrelevant, irregular, irresponsible, irrational, irreversible. The consonant doubling (im+m, il+l, ir+r) gives a clue to the correct prefix.
Practice
Parking here is ___.
Changing the past is completely.
Put the words in the correct order:
"Mis-" means wrongly or badly: misunderstand, misspell, mistreat, mislead, miscalculate. "Non-" means not of a particular type: non-profit, non-fiction, non-verbal, non-stop. "Non-" is often hyphenated in British English (non-profit) but written as one word in American English (nonprofit). Unlike other negative prefixes, "non-" can attach to nouns and longer compound words.
Practice
She ___ what I said and thought I was being rude.
The charity is aorganisation.
Put the words in the correct order: