Theory:

The following is a list of common antonyms:
  

Words

Antonyms

accurate

 inaccurate

agree

 disagree

answer

 question

apart

 together

can

 cannot, can't

capable

 incapable

captive

 free

cheap

 expensive

cold

 hot

combine

 separate

come

 go

common

 rare

dull

 bright, shiny

empty

 full

end

 begin, start

gentle

 rough

glad

 sad, sorry

gloomy

 cheerful

go

 stop

good

 bad, evil

guilty

 innocent

happy

 sad

hate

 love

healthy

 diseased, ill, sick

heaven

 hell

heavy

 light

help

 hinder

high

 low

hill

 valley

hot

 cold

humble

 proud

ill

 healthy, well

lenient

 strict

light

 dark, heavy

like

 dislike, hate

rich

 poor

tough

 easy, tender

unfold

 fold

unknown

 known

unqualified

 qualified

up

 down

vacant

 occupied

wax

 wane

weak

 strong

wet

 dry

white

 black

wide

 narrow

win

 lose

within

 outside

young

 old

 
Important!
Click here for an extensive list of antonyms.