35 Most Common Prefixes in English with their Meanings

Prefixes are fascinating tools in our language that allow us to alter the meaning of words with just a few letters. When we add these meaningful bits to the beginning of a word, we can transform the entire context, giving us the power to craft a vast array of nuanced expressions. Understanding prefixes is essential for our mastery of the English language, since they are foundational components that help us decipher meaning, even in words we may have never encountered before.

Definition of Prefixes

A prefix is a group of letters added to the beginning of a word to change its meaning.
For example:

happy → unhappy (not happy)
possible → impossible (not possible)

Prefixes do not change the word’s part of speech but alter its meaning.

Why Learn Prefixes?

Expand Vocabulary: Learn one prefix, and you can understand many words.
Improve Reading Skills: Recognizing prefixes makes it easier to guess meanings of unfamiliar words.
Boost Spelling: Knowing prefixes can help you spell longer words correctly.

Common Types of Prefixes

1. Negative Prefixes

These prefixes make a word mean its opposite.
Examples:

un-: unhappy (not happy)
in-: inactive (not active)
im-: impossible (not possible)
dis-: disagree (not agree)
non-: nonfiction (not fiction)

2. Number Prefixes

These prefixes indicate numbers.
Examples:

uni-: uniform (one form)
bi-: bicycle (two wheels)
tri-: triangle (three sides)
quadri-: quadrilateral (four sides)
multi-: multilingual (many languages)

3. Time and Order Prefixes

These prefixes show when something happens or the order.
Examples:

pre-: preview (see before)
post-: postgraduate (after graduation)
fore-: forecast (predict beforehand)
re-: redo (do again)
ex-: ex-president (former president)

4. Degree or Size Prefixes

These prefixes indicate the size, extent, or intensity.
Examples:

super-: superstar (very famous person)
over-: overwork (work too much)
under-: underpaid (paid too little)
mini-: miniskirt (small skirt)
mega-: megabyte (large unit of digital data)

5. Location or Position Prefixes

These prefixes describe location or position.
Examples:

sub-: subway (underground railway)
inter-: international (between nations)
trans-: transport (move across)
mid-: midnight (middle of the night)
circum-: circumnavigate (sail around)

Table of Common Prefixes

Prefix	Meaning	Example	Meaning of Example
un-	not	unfair	not fair
pre-	before	preheat	heat before
re-	again	rewrite	write again
mis-	wrongly	misplace	place wrongly
anti-	against	antifreeze	against freezing

Common Prefixes in English

Tri–

Meaning: Three
E.g. triangle, tripod, etc.
The sum of all the angles of a triangle is 180 degrees.

In–

Meaning: Not
E.g. inconvenience, infield, innocent, etc.
I don’t want to put you to any inconvenience.

Mis–

Meaning: Wrong, wrongly
E.g. misunderstand, misfire, misfortune, misbehavior, etc.
This misbehavior will certainly go against his chances of promotion.

Ex–

Meaning: Former, older, out of, away from, lacking
E.g. exhale, ex-wife, excentral, exclude
We can exclude the possibility of total loss from our calculations.

Dis–

Meaning: Not, opposite of, reverse
E.g. disagree, disappear, disregard, disqualified, disqualify, etc.
Lack of education will disqualify you for most good jobs.

Re–

Meaning: Again
E.g. return, remainder, re-useable, refold, regain, etc.
She will now begin occupational therapy to regain the use of her hands.

Anti–

Meaning: Against
E.g. antifreeze, antipathy, antibiotic, antisocial, anti-war, etc.
Lack of antifreeze is a major cause of highway breakdowns.

Pre–

Meaning: Before
E.g. prefix, preschool, pre-intermediate, pre-tax
But he is heading off to preschool, and we wanted to get him some educational programs.

Post–

Meaning: Later
E.g. post-office, postgraduate, postscript
There was the usual romantic postscript at the end of his letter.

Auto–

Meaning: Self,
E.g. automatic, automobile
The movements of machines are completely automatic, you only need to start and stop the machines.

Un–

Meaning: Not
E.g. unhappy, unfriendly, unpleasant, unwell, etc.
This unpleasant incident detracted from our enjoyment of the evening.

Ir–

Meaning: Not
E.g. irrelevant, irregular, irresponsible, etc.
Thick patchy fog and irresponsible driving were to blame.

Im–

Meaning: Not
E.g. impolite, impossible, immortal, impatient, etc.
Don’t be so impatient! The bus will be here soon.

Over–

Meaning: Too, in excess of
E.g. overlook, overdose, overdue, overall, overconfident, etc.
He proved overconfident on the witness stand.

Semi–

Meaning: Half
E.g. semifinal, semicircle, semi-final, semiformal, semiannual, etc.
I had never been to a semiformal dance before, and now was my chance.