PREFIXES

PREFIXES

A prefix is placed at the beginning of a word to modify or change its meaning. This is a list of the most common prefixes in English, together with their basic meaning and some examples. You can find more detail or precision for each prefix in any good dictionary.

A prefix goes at the beginning of a word. A suffix goes at the end of a word.

The origins of words are extremely complicated. You should use this list as a guide only, to help you understand possible meanings. But be very careful, because often what appears to be a prefix is not a prefix at all. Note also that this list does not include elements like "auto-" or " bio-", because these are "combining forms", not prefixes.

prefix		meaning	examples
a-	also an-	not, without	atheist, anaemic
a-		to, towards	aside, aback
		in the process of, in a particular state	a-hunting, aglow
a-		of	anew
		completely	abashed
ab-	also abs-	away, from	abdicate, abstract
ad-	also a-, ac-, af-, ag- al-, an-, ap-, at- as-, at-	movement to, change into, addition or increase	advance, adulterate, adjunct, ascend, affiliate, affirm, aggravate, alleviate, annotate, apprehend, arrive, assemble, attend
ante-		before, preceding	antecedent, ante-room
anti-	also ant-	opposing, against, the opposite	anti-aircraft, antibiotic, anticlimax, Antarctic
be-		all over, all around	bespatter, beset
		completely	bewitch, bemuse
		having, covered with	bejewelled
		affect with (added to nouns)	befog
		cause to be (added to adjectives)	becalm
com-	also co-, col-, con-, cor-	with, jointly, completely	combat, codriver, collude, confide, corrode
contra-		against, opposite	contraceptive
counter-		opposition, opposite direction	counter-attack, counteract
de-		down, away	descend, despair, depend, deduct
		completely	denude, denigrate
		removal, reversal	de-ice, decamp
dia-	also di-	through, across	diagonal
dis-	also di-	negation, removal, expulsion	disadvantage, dismount, disbud, disbar
en-	also em-	put into or on	engulf, enmesh
		bring into the condition of	enlighten, embitter
		intensification	entangle, enrage
ex-	also e-, ef-	out	exit, exclude, expand
		upward	exalt, extol
		completely	excruciate, exasperate
		previous	ex-wife
extra-		outside, beyond	extracurricular
hemi-		half	hemisphere
hyper-		beyond, more than, more than normal	hypersonic, hyperactive
hypo-		under	hypodermic, hypothermia
in-	also il-, im-	not, without	infertile, inappropriate, impossible
	also il-, im-, ir-	in, into, towards, inside	influence, influx, imbibe
infra-		below	infrared, infrastructure
inter-		between, among	interact, interchange
intra-		inside, within	intramural, intravenous
non-		absence, negation	non-smoker, non-alcoholic
ob-	also oc-, of-, op-	blocking, against, concealing	obstruct, occult, offend, oppose
out-		surpassing, exceeding	outperform
		external, away from	outbuilding, outboard
over-		excessively, completely	overconfident, overburdened, overjoyed
		upper, outer, over, above	overcoat, overcast
peri-		round, about	perimeter
post-		after in time or order	postpone
pre-		before in time, place, order or importance	pre-adolescent, prelude, precondition
pro-		favouring, in support of	pro-African
		acting for	proconsul
		motion forwards or away	propulsion
		before in time, place or order	prologue
re-		again	repaint, reappraise, reawake
semi-		half, partly	semicircle, semi-conscious
sub-	also suc-, suf-, sug-, sup-, sur-, sus-	at a lower position	submarine, subsoil
		lower in rank	sub-lieutenant
		nearly, approximately	sub-tropical
syn-	also sym-	in union, acting together	synchronize, symmetry
trans-		across, beyond	transnational, transatlantic
		into a different state	translate
ultra-		beyond	ultraviolet, ultrasonic
		extreme	ultramicroscopic
un-		not	unacceptable, unreal, unhappy, unmanned
		reversal or cancellation of action or state	unplug, unmask
under-		beneath, below	underarm, undercarriage
		lower in rank	undersecretary
		not enough	underdeveloped

I WISH/ IF ONLY

I WISH/ IF ONLY

Wishes about the present

We use wish with past Tense forms (simple and continuous) to express regret about present situations:

• I wish I was taller = (I’m not very tall)
• I wish I was going with you = (but I'm not)

• I wish you were more help. = (you are not) I wish I were can replace I wish I was.

To many people, I wish I were sounds more correct:

• I wish I were taller.

We use wish with could to express a wish for a present situation to be different:

• I wish I could use a computer well.
• I wish I would tell her about it.
• I wish I could tell her about it.

Past Simple > present>I wish I knew the answer. (= I don’t know)

Past Simple > present > I wish I was /were better at sports. (= I'm not)

Past Continuous > present > I wish I was /were going with you. (= I'm not)     

Could > present > I wish I could give you an answer. (= I can't)

Would > future > I wish you would be quiet. (= Your talking irritates me.)

Past Perfect > past > I wish I had known you then. (= but I didn't)

Could have > past> I wish I could have explained. (= I wasn't able to)

Wishes about the future

We use wish with would to say how we would like somebody to behave in the future:

X I wish you to stop talking.

/I wish you would stop talking.

X I wish that they will stop arguing.

/I wish they would stop arguing.

• We can also use this pattern in situations that do not involve people:

I wish this car would go faster.

Wishes about the past

We use wish with the Past Perfect when we have

Regrets about the past:

I wish I hadn't taken your advice. (= but I did)

I wish she could have come. (= but she didn't)

If only

If only can be more emphatic than I wish. The verb forms after if only are the same as the patterns with wish:

If only I had more money! (= but I haven't)

If only I was going on holiday with you!

If only you were here. (= but you re not)

If only the sun would come out!

If only you could be here! (= but you're not)

If only I'd listened to you! (=but I didn't )

If only he could have explained! (=but he wasn't able to)