Common Prefixes in English

If you were a prefix, you could change the same word in different ways. You could make a cycle a unicycle, a bicycle, or a tricycle.

A prefix is a letter or a group of letters attached to the beginning of a word (or word root) that partly indicates its meaning.

For example, the word prefix itself begins with the prefix pre-, which generally means “before” or “in front of.”

They can also make a word negative or express relations of time, place or manner. Here are some examples:

Base word	Type of meaning	Prefixed word
possible	opposite	impossible
able	opposite/negation	unable
payment	negation	non-payment
war	time (before)	pre-war
terrestrial	place (outside of/beyond)	extraterrestrial
cook	manner (too much)	overcook

Example:

1. That he was unable to do, even if it were true, which he doubted.
2. It is virtually impossible that he had all the same information as the actual president.
3. The meat was overcooked and quite tasteless.

The most common prefixes

Prefix	Meaning	Examples
a-, an-	without, lack of, not	amoral, acellular, abyss, achromatic, anhydrous
ante-	before, earlier, in front of	antecedent, antedate, antemeridian, anterior
anti-	against/opposed to	anti-government, anti-racist, anti-war
auto-	self	autobiography, automobile
circum-	around, about	circumvent, circumnavigate, circumscribe
co-	with, together	co-pilot, co-worker, co-exist, co-author
com-, con-	together, with	companion, commingle, contact, concentrate
contra-, contro-	against, opposite	contradict, contrast, contrary, controversy
de-	reverse or change	de-classify, decontaminate, demotivate
dis-	reverse or remove	disagree, displeasure, disqualify
down-	reduce or lower	downgrade, downhearted
en-	put into, cover with	enclose, entangle, enslave, encase
ex-	out of, from, former	extract, exhale, excavate, ex-president
extra-	beyond, outside, more than	extraordinary, extraterrestrial
hetero-	different, other	heterosexual, heterodox, heterogeneous
homo-, homeo-	same, alike	homonym, homophone, homeostasis
hyper-	extreme, over, more, beyond	hyperactive, hypertension
il-, im-, in-, ir-	not, without	illegal, impossible, insecure, irregular
inter-	between, among	interactive, international
intra-, intro-	within, inside	intravenous, intragalactic, introvert
macro-	large, prominent	macroeconomics, macrostructure, macrocosm
micro-	very small	microscope, microcosm, microbe
mono-	one, single, alone	monocle, monologue, monogamy, monotony
mega-	very big, important	megabyte, mega-deal, megaton
mid-	middle	midday, midnight, mid-October
mis-	incorrectly, badly	misaligned, mislead, misspelt
non-	not	non-payment, non-smoking
omni-	all, every	omniscient, omnivorous, omniscient, omnidirectional
over-	too much	overcook, overcharge, overrate
out-	go beyond	outdo, out-perform, outrun
post-	after	post-election, post-war
pre-	before	prehistoric, pre-war
pro-	in favour of	pro-communist, pro-democracy
re-	again	reconsider, redo, rewrite
semi-	half	semicircle, semi-retired
sub-	under, below	submarine, sub-Saharan
sym-, syn-	same time, together	symmetry, symposium, synchronize, synapse
super-	above, beyond	super-hero, supermodel
tele-	at a distance	television, telepathic
trans-	across	transatlantic, transfer
tri-	three, every third	tricycle, trimester, triangle, triathlon
ultra-	extremely	ultra-compact, ultrasound
un-	remove, reverse, not	undo, unpack, unhappy
under-	less than, beneath	undercook, underestimate
uni-	one, single	unicorn, unicellular, unicycle, unilateral
up-	to the top or north, higher/better	upbeat, updo, upgrade, upload, uphill, upstage, upscale, up-tempo