Common Prefixes:

Placed before a word It changes the meaning

Pre fix	Meaning	Examples
un-	not or opposite	undo, unhappy, unimportant
re-	again or back	redo, remix, return
in-	not or in	invisible
im-	not or in	imperfect
ig-	not	ignorant
il-	not or in	illiterate
ir-	not	irresponsible
dis-	apart	disagree
di-	away	diverge
dif-	opposite	different
en-	to cause to be in a place or state	enact, encourage, encircle
em-	to cause to be in a place or state	employ, empower
non-	not or opposite	nonthreatening, nonfiction, nonstop
in-	in	inside, insight, invest
im-	in	impress
il-	in	illumine
over-	over, too much	overdo, overstate, overload, oversee
mis-	wrong, incorrect	misunderstand, misplace
sub-	below, beneath, under, secondary	subconscious, substandard
pre-	before	predawn, preset, preview
inter-	between, among	intermix, intermingle, intertwine
fore-	before	foretaste, foreclose, forehand
de-	away from, out of	defrost, deforest, deflate
trans-	across	transmit, transfusion, transport
super-	over, big, extreme	superhighway, superhuman
semi-	half, part	semicircle, semiconductor
anti-	against	antidepressant, antifreeze
mid-	middle	midday, midsummer, midnight
under-	below, not enough	underfed, underweight

Common Prefixes