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
With adjectives and past participles, un- reverses the meaning: happy → unhappy; known → unknown; expected → unexpected. With verbs, it signals undoing an action: lock → unlock; pack → unpack; do → undo. Before an adjective it means "not this way." Before a verb it means "reverse this action."
Un- attaches mainly to Germanic (Anglo-Saxon) roots: unhappy, unknown, undo. In- attaches mainly to Latin-origin words: independent, invisible, incorrect. Dis- adds a sense of active opposition: disagree, disapprove. For everyday adjectives and almost any verb, un- is nearly always the correct choice.
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. In Spanish it usually maps to in- / des-.
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.