Positive/Negative
* Synonym: happy / joyful
* Antonym: happy / sad
Large/Small
* Synonym: gigantic / enormous
* Antonym: gigantic / tiny
Hot/Cold
* Synonym: scorching / boiling
* Antonym: scorching / freezing
Fast/Slow
* Synonym: rapid / swift
* Antonym: rapid / sluggish
Strong/Weak
* Synonym: powerful / mighty
* Antonym: powerful / frail
Light/Dark
* Synonym: bright / luminous
* Antonym: bright / shadowy
Good/Bad
* Synonym: excellent / superb
* Antonym: excellent / terrible
Active/Passive
* Synonym: energetic / lively
* Antonym: energetic / lazy
Clean/Dirty
* Synonym: spotless / pristine
* Antonym: spotless / filthy
Honest/Dishonest
* Synonym: truthful / sincere
* Antonym: truthful / deceitful
Brave/Cowardly
* Synonym: courageous / valiant
* Antonym: courageous / timid
Rich/Poor
* Synonym: wealthy / affluent
* Antonym: wealthy / impoverished
Wise/Foolish
* Synonym: intelligent / insightful
* Antonym: intelligent / naive
Friendly/Unfriendly
* Synonym: amiable / congenial
* Antonym: amiable / hostile
Busy/Idle
* Synonym: occupied / engaged
* Antonym: occupied / relaxed
Important/Unimportant
* Synonym: vital / crucial
* Antonym: vital / trivial
Difficult/Easy
* Synonym: challenging / arduous
* Antonym: challenging / simple
Complex/Simple
* Synonym: intricate / elaborate
* Antonym: intricate / basic
Open/Closed
* Synonym: unlocked / unsealed
* Antonym: unlocked / shut
Wet/Dry
* Synonym: damp / moist
* Antonym: damp / arid
Old/New
* Synonym: ancient / antique
* Antonym: ancient / modern
Note: This is just a small sample, and there are many other synonyms and antonyms out there! You can find more by using a thesaurus.