Negative prefixes

The most common negative prefix is un-, but there are also in-, il-, im-, ir-, dis- and non-.

Un-, like dis-, can be added to many adjectives, adverbs, verbs and nouns to give them the opposite meanings, e.g.:

Adjectives: unpopular, unhappy, uncomfortable, unfriendly, unfashionable, disabled, disloyal, disorganised

Adverbs: unkindly, unselfishly, disapprovingly, dishonestly

Verbs: undo, , discontinue,

Nouns: unkindness, unpleasantness, displeasure, disrespect

In-, il-, im- and ir- can be added to many adjectives, adverbs and nouns, BUT NOT VERBS, to give them the opposite meanings, e.g.:

Adjectives: inexperienced, incorrect, inaccurate, illegal, illegible, impossible, improbable, impatient, irrational, irregular

Adverbs: inaccurately, illegally, impossibly, irregularly

Nouns: insincerity, inaccuracy, illegality, impossibility, immorality, irregularity

Non- can be added to some adjectives and nouns, e.g.

Adjectives: non-returnable

Nouns: non-fiction,

As you can see from the examples above, there are no absolute rules about when we should use a particular negative prefix. One can only say:

1. that il- is commonly added to words beginning with l, such as illegal. But then we also have words like unlikely and disloyal, where un- and dis- are used before words beginning with l to form their opposites.


2. that im- is commonly added to words beginning with m and p, like impossible and impolite, but then we also have words like unpleasant, dispassionate, unmask, non-payment and where un-, dis-, and non- are used before words beginning with p and m to form their opposites.


3. that ir- is commonly added to words beginning with r, such as irrational and irregular, but then we also have words like unreal, disrespectful and non-returnable, where un-, dis-, and non- are used before words beginning with r to form their opposites.