Common Prefixes in English - Prefix Examples

What Are Prefixes?

A prefix is a group of letters added to the beginning of a word to change its meaning. Prefixes do not change a word’s grammatical category (noun, verb, adjective), but they modify its meaning.

For example:

Moral → Amoral (prefix "a-" means "without")
Appear → Disappear (prefix "dis-" means "opposite of")

Why Are Prefixes Important?

Help in guessing the meaning of new words.
Make it easier to expand vocabulary.
Used in everyday English in conversations, writing, and reading.

Illustration of Common Prefixes in English

List of Common Prefixes in English

Negative Prefixes

These prefixes give a word a negative or opposite meaning.

Prefix	Meaning	Examples
a-, an-	Without, lack of, not	Amoral, abyss, anhydrous
anti-	Against, opposite of	Anticlimax, antibody, antiseptic
contra-, contro-	Against, opposite	Contradict, controversy, contrast
de-	Down, off, away from	Devalue, deactivate, debug
dis-	Not, apart, away	Disappear, disagree, dissect
il-, im-, in-, ir-	Not, without	Illegal, immoral, inconsiderate, irresponsible
non-	Not, without	Nonfiction, nonessential, nonaggressive
un-	Not, lacking, opposite of	Unfinished, unskilled, ungraceful

✔ Example Sentences:

The scientist studied asexual reproduction.
The lawyer argued that the contract was invalid.

Size and Number Prefixes

These prefixes indicate size, number, or amount.

Prefix	Meaning	Examples
bi-	Two	Bicycle, bilingual, biweekly
macro-	Large, prominent	Macroeconomics, macrocosm
micro-	Very small	Microscope, microbe, microcosm
mono-	One, single	Monocle, monologue, monotony
multi-	Many	Multitask, multilingual, multipurpose
omni-	All, every	Omniscient, omnidirectional
poly-	Many	Polygon, polyglot, polyester
semi-	Half, partly	Semicircle, semifinal, semi-conscious
tri-	Three, every third	Tricycle, triangle, triathlon
uni-	One, single	Unicorn, unicellular, unilateral

✔ Example Sentences:

The athlete participated in a triathlon.
The scientist examined a microscopic organism.

Time and Order Prefixes

These prefixes show time or order in a sequence.

Prefix	Meaning	Examples
ante-	Before, earlier, in front of	Antecedent, antemeridian
ex-	Out of, from, former	Ex-president, extract, excavate
extra-	Beyond, outside, more than	Extracurricular, extravagant
post-	After, behind	Postmortem, postoperative, postscript
pre-, pro-	Before, forward	Precede, predict, project, prologue
re-	Again	Reelect, resubmit, redo
tele-	From or over a distance	Telecommunications, television, telephone
trans-	Across, beyond, through	Transmit, translation, transfer

✔ Example Sentences:

The book includes a prologue explaining the story.
The new student had to redo his assignment.

Location and Position Prefixes

These prefixes show location, direction, or position.

Prefix	Meaning	Examples
circum-	Around, about	Circumnavigate, circumflex
co-	With, together	Co-pilot, co-exist, co-worker
com-, con-	Together, with	Companion, concentrate
en-	Put into, cover with	Enclose, entangle, enslave
in-	In, into	Insert, infiltrate, inspection
inter-	Between, among	Intersect, intervene, interstellar
intra-, intro-	Within, inside	Intravenous, intramural, introvert
sub-	Under, lower	Submarine, subsidiary, substandard
super-	Above, beyond	Supermarket, superstar, superhuman
up-	To the top or north, higher/better	Upload, upgrade, upscale

✔ Example Sentences:

The submarine went deep into the ocean.
The two teams had an international match.

Degree and Intensity Prefixes

These prefixes describe the degree or intensity of an action or state.

Prefix	Meaning	Examples
auto-	Self, same	Autopilot, autobiography, autofocus
hetero-	Different, other	Heterosexual, heterogeneous
homo-, homeo-	Same, alike	Homonym, homophone, homeostasis
hyper-	Over, more, beyond	Hyperactive, hypersensitive
hypo-	Below, less than	Hypodermic, hypothermia
sym-, syn-	Same time, together	Symmetry, synchronize

✔ Example Sentences:

The child was very hyperactive.
Scientists study homeostasis in the human body.

Spelling Changes with Prefixes

Double Letters

im- + mature = immature
il- + legal = illegal

Hyphen Use

Self-aware, ex-president, co-worker

Prefix does not change spelling

happy → unhappy
do → redo

Common Mistakes with Prefixes

Using the wrong prefix

❌ Mispossible → ✔ Impossible

Forgetting the spelling change

❌ Inlegal → ✔ Illegal

Using a prefix that doesn’t exist

❌ Underfast → ✔ No correct form

FAQs About Prefixes

What is the most common prefix in English?

The prefix "un-" (meaning "not") is one of the most common, as in unhappy, unclear, unfair.

How do prefixes change word meanings?

Prefixes modify the meaning of the root word. For example, happy → unhappy (not happy), do → redo (do again).

Do prefixes change spelling?

Sometimes! For example, "legal" changes to "illegal" because "il-" is used before "l".

Can I add any prefix to any word?

No, not all prefixes work with every word. For example, "undoor" is incorrect, but "unlock" is correct.

What’s the difference between "pre-" and "post-"?

"Pre-" means before (preview = look before).
"Post-" means after (postgraduate = after graduation).