Prefix · negation / reversal
The most common negative prefix in English: turns happy into unhappy and lock into unlock.
Written by Bryan López, English teacher · Updated
Un- has two uses in one. With adjectives and participles, it negates the meaning: "it is not ...". With verbs, it shows undoing an action: "taking back what was done". A simple rule to remember it: before an adjective it means "is not", and before a verb it means "undo".
Un- is the most common of the English negative prefixes, and it works with adjectives, participles and verbs. If you are unsure whether to use un-, in- or dis-, check the dictionary: most words accept only one of them. As a rule of thumb, un- is the natural choice for everyday words of Germanic origin, while in- and dis- go with words of Latin or French origin.
Attach directly in front of adjectives, past participles, or verbs with no spelling change:
The spelling of the root never changes, even when it starts with n: unnecessary, unnatural. Pronunciation is always /ʌn/, rhyming with "sun".
un-/ʌn/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
Latin-origin words take in-, not un-. "Independent" comes from Latin and therefore uses in-.
"Abnormal" is the standard adjective. "Unnormal" is not used in standard English.
A trick to remember it
Use "unhappy" and "unlock" as your anchors. Un- before an adjective = "not ___"; un- before a verb = "reverse ___." This single rule gives you access to hundreds of words.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
Which completes: "Can you ___ the door? I forgot my key inside."
Exercise 3 · Pick the right one
Why is "undependent" wrong?
The prefix un- the most common negative prefix in English: turns happy into unhappy and lock into unlock.
The prefix un- is pronounced /ʌn/. For example, "unhappy".
"happy" becomes "unhappy". It is a typical example of the un- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.