An Antonym or Opposite is a word which – generally speaking – has the opposite meaning to another word. For example, the following are antonyms:

big ↔ small
fat ↔ thin
tall ↔ short
old ↔ young
male ↔ female

Some words will have more than one antonym depending on context. For example

big ↔ small, tiny, miniature

And the antonym of antonym? That’s synonym which describes a word having the same meaning as another word.

Forming Antonyms

In many cases there’s no obvious relationship between a word and its antonym. For example these two words have completely separate etymologies:

hot ↔ cold

However, English also sometimes forms antonyms by using prefixes such as:

• de-
• dis-
• il-
• im-
• in-
• in/ex-
• ir-
• non-
• re-
• un-

Examples of opposite pairs formed like this include:

arm ↔ disarm
code ↔ decode
complete ↔ incomplete
internal ↔ external
legal ↔ illegal
possible ↔ impossible
regular ↔ irregular
sense ↔ nonsense

Certainly when these words or prefixes appear in the classroom you can explain how they work to form antonyms.

Use

In the TEFL‏‎ classroom antonyms can be used with your students when looking at vocabulary‏‎ and explanations.

Rather than teach a single word, you can teach the word and its antonym, so rather than just teach cheap you can teach expensive along with it.

And when a student asks for the meaning of a word, rather than explain it directly (or as part of your explanation) you can use its antonym, e.g.

S: What does absent mean?

T: It’s the opposite of present.

Common Antonyms

The following is a list of antonyms which learners of English at Upper-Intermediate level should be aware of.

absence ↔ presence
accept ↔ refuse
accurate ↔ inaccurate
advantage ↔  disadvantage
alive ↔ dead
always ↔ never
ancient ↔ modern
answer ↔ question, query
approval ↔ disapproval
approached ↔ receded, departed
abundant ↔ scarce
admit ↔ deny
advance ↔ retreat, retire
artificial ↔ natural
arrival ↔ departure
ascend ↔ descend
attack ↔ defense
attractive ↔ repulsive
attention ↔ inattention
asleep ↔ awake
ally ↔ enemy
agree ↔ disagree
bad ↔ good
backward ↔ forward, onward
bend ↔ straighten
beautiful ↔ ugly
beginning ↔ ending
below ↔ above
bent ↔ straight
big ↔ small, little
blunt ↔ sharp
better ↔ worse
best ↔ worst
blame ↔ praise
bless ↔ curse
bitter ↔ sweet
borrow ↔ lend
bravery ↔ cowardice
build ↔ destroy, demolish
bold ↔ timid, meek
bright ↔ dull
broad ↔ narrow
clear ↔ vague, cloudy
careful ↔ rush, careless
calm ↔ troubled
capable ↔ incapable
captivity ↔ freedom, liberty
cellar ↔ attic
cheap ↔ dear, expensive
close ↔ distant
clever ↔ stupid
cold ↔ hot
combine ↔ separate
clockwise ↔  anti-clockwise
correct ↔ incorrect
conceal ↔ reveal
come ↔ go
common ↔ rare
comfort ↔ discomfort
courage ↔ cowardice
cruel ↔ kind
courteous ↔  discourteous, rude
cunning ↔ simple
dainty ↔ clumsy
danger ↔ safety
dark ↔ light
deep ↔ shallow
decrease ↔ increase
definite ↔ indefinite
demand ↔ supply
despair ↔ hope
disappear ↔ appear
disease ↔ health
discourage ↔ encourage
dismal ↔ cheerful
doctor ↔ patient
dry ↔ wet
dull ↔ clear, bright
dusk ↔ dawn
early ↔ late
easy ↔ difficult
ebb ↔ flow
East ↔ West
economize ↔ waste
encourage ↔ discourage
entrance ↔ exit
employer ↔ employee
empty ↔ full
excited ↔ calm
end ↔ beginning
expand ↔ contract
expensive ↔  inexpensive, cheap
export ↔ import
exterior ↔ interior
external ↔ internal
fail ↔ succeed
false ↔ true
feeble ↔ sturdy, strong, powerful
foolish ↔ wise
fast ↔ slow
few ↔ many
famous ↔ unknown
forelegs ↔ hind legs
fat ↔ thin
find ↔ lose
first ↔ last
freedom ↔ captivity
fold ↔ unfold
frequent ↔ seldom
forget ↔ remember
found ↔ lost
fresh ↔ stale
friend ↔ enemy
fortunate ↔ unfortunate
frank ↔ secretive
full ↔ empty
generous ↔ mean
gentle ↔ rough
gather ↔ distribute
glad ↔ sorry
gloomy ↔ cheerful
giant ↔ dwarf, pygmy
granted ↔ refused
great ↔ minute, small, little
guardian ↔ ward
guest ↔ host
guilty ↔ innocent
happy ↔ sad, miserable
hard ↔ soft
harmful ↔ harmless
hasten ↔ dawdle
hate ↔ love
healthy ↔ unhealthy, ill, diseased
here ↔ there
heavy ↔ light
height ↔ depth
hero ↔ coward
hill ↔ valley
horizontal ↔ vertical
hinder ↔ aid, help
honest ↔ dishonest
humble ↔ proud
hunger ↔ thirst
imitation ↔ genuine
immense ↔ tiny, minute
imprison ↔ free
include ↔ exclude
increase ↔ decrease
inhabited ↔ uninhabited
inferior ↔ superior
inside ↔ outside
intelligent ↔  unintelligent, stupid
inhale ↔ exhale
interior ↔ exterior, outside
interesting  ↔  uninteresting, dull
internal ↔ external
intentional ↔ accidental
join ↔ separate
junior ↔ senior
justice ↔ injustice
king ↔ subject
knowledge ↔ ignorance
laugh ↔ cry
lawful ↔ unlawful
lazy ↔  industrious, energetic
land ↔ sea
landlord ↔ tenant
large ↔ little, small
last ↔ first
lawyer ↔ client
lecturer ↔ student
lender ↔ borrower
lengthen ↔ shorten
left ↔ right
less ↔ more
light ↔ dark, heavy
like ↔ dislike, unlike
likely ↔ unlikely
leader ↔ follower
little ↔ large, much, big
lofty ↔ lowly
long ↔ short
loud ↔ soft
loss ↔ find, win
low ↔ high
loyal ↔ disloyal
mad ↔ sane
magnetize ↔ demagnetize
master ↔ servant
mature ↔ immature
maximum ↔ minimum
me ↔ you
merry ↔ mirthless, sad
minority ↔ majority
miser ↔ spendthrift
misunderstand ↔ understand
narrow ↔ wide
near ↔ far, distant
neat ↔ untidy
new ↔ old
night ↔ day
noisy ↔ quiet
North ↔ South
obedient ↔ disobedient
odd ↔ even
offer ↔ refuse
open ↔ shut
optimist ↔ pessimist
out ↔ in
parent ↔ child
past ↔ present
patient ↔ impatient
peace ↔ war
permanent ↔ temporary
please ↔ displease
plentiful ↔ scarce
poetry ↔ prose
possible ↔ impossible
poverty ↔ wealth
powerful ↔ feeble, weak
polite ↔ impolite, rude
private ↔ public
prudent ↔ imprudent
pretty ↔ unsightly, ugly
pure ↔ impure
qualified ↔ unqualified
rapid ↔ slow
regularly ↔ irregularly
rich ↔ poor
right ↔ wrong, left
rigid ↔ pliable, soft
rough ↔ smooth
satisfactory ↔  unsatisfactory
security ↔ insecurity
scatter ↔ collect
serious ↔ trivial
second-hand ↔ new
sense ↔ nonsense
shopkeeper ↔ customer
singular ↔ plural
simple ↔ complicated
slim ↔ thick, stout
solid ↔ liquid
sober ↔ drunk
speaker ↔ listener
sour ↔ sweet
sorrow ↔ joy
sow ↔ reap
stand ↔ lie
straight ↔ crooked
strong ↔ weak
success ↔ failure
sunny ↔ cloudy
take ↔ give
tall ↔ short
tame ↔ wild
teacher ↔ pupil
thick ↔ thin
tight ↔ slack, loose
top ↔ bottom
transparent ↔ opaque
truth ↔ untruth, lie
up ↔ down
vacant ↔ occupied
valuable ↔ valueless
victory ↔ defeat
virtue ↔ vice
visible ↔ invisible
voluntary ↔ compulsory
vowel ↔ consonant
wax ↔ wane
wisdom ↔ folly
within ↔ without