For example, the prefix un- can be attached to the adjective happy to create the negative adjective unhappy.
Note that there is no difference in meaning between these two forms.
| affirmative | | negative |
| negative prefix | | not |
| Tom is happy. | Tom is unhappy. | Tom is not happy. |
Words that take a– as a negative prefix always begin with a consonant.
| affirmative | | negative |
| political | apolitical |
| sexual | asexual |
| theist | atheist |
Words that take dis– as a negative prefix may begin with a vowel or a consonant.
| affirmative | | negative |
| agree | disagree |
| comfort | discomfort |
| mount | dismount |
| orient | disorient |
Words that take il– as a negative prefix always begin with the letter l.
| affirmative | | negative |
| legal | illegal |
| legible | illegible |
| literate | illiterate |
| logical | illogical |
Words that take im– as a negative prefix always begin with the letter m or p.
| affirmative | | negative |
| mobile | immobile |
| moral | immoral |
| perfect | imperfect |
| possible | impossible |
Words that take in– as a negative prefix can begin with a vowel (except i or u) or a consonant.
| affirmative | | negative |
| accurate | inaccurate |
| eligible | ineligible |
| organic | inorganic |
| decent | indecent |
| sane | insane |
Note: There are many words that begin with in– that are not words with a negative prefix. For example:
| word | | does not mean |
| incline | not cline |
| indulge | not dulge |
| insist | not sist |
| invoke | not voke |
Words that take ir– as a negative prefix always begin with the letter r.
| affirmative | | negative |
| rational | irrational |
| reconcilable | irreconcilable |
| regular | irregular |
| resistible | irresistible |
Words that take non– as a negative prefix may begin with a vowel or a consonant.
| affirmative | | negative |
| conformist | nonconformist |
| essential | nonessential |
| fiction | nonfiction |
| sense | nonsense |
Words that take un– as a negative prefix may begin with a vowel or consonant.
| affirmative | | negative |
| able | unable |
| interesting | uninteresting |
| usual | unusual |
| comfortable | uncomfortable |
| helpful | unhelpful |
| prepared | unprepared |
Remember, not all words that appear to have a negative prefix are negative.
| word | | does not mean |
| alike | not like |
| discuss | not cuss |
| universe | not iverse |
| illuminate | not luminate |
| important | not portant |
| involve | not volve |
| irrigate | not rigate lawlessenglish.com
Exercise 1
Exercise 2
Exercise 3 |