This is list of common opposite adjectives in English:

• slow – fast
• clean – dirty
• curly – straight
• difficult – easy
• good – bad
• early – late
• fat – thin
• full – empty
• hot – cold
• happy – sad/unhappy
• hardworking – lazy
• modern – traditional
• new – old
• nice – nasty
• cruel – kind
• dry – wet
• early – late
• hungry – full
• narrow – wide
• normal – strange
• on – off
• public – private
• light – heavy
• loose – tight
• big – small
• bad – good
• deep – shallow
• dark -light
• lazy – hardworking
• short – tall
• insane – sane
• poor – wealthy
• cheap -expensive
• wide – narrow
• healthy – sick
• friendly – unfriendly
• tidy – messy
• patient – impatient
• dishonest – honest
• happy – unhappy