Some antonyms (i-adjectives)

hot (thing)

cold (to the touch); chilly; icy; freezing

cold (e.g. weather)

hot (weather, etc.); warm

bright; colourful

dark; gloomy

far; distant

near; close; short (distance)

hard; solid; strong; stiff

soft; tender; limp

spacious; vast; wide

narrow; confined; small

shallow; superficial

deep; profound

thick

thin

early; (fast)

fast; quick

slow; late (e.g. "late at night")

cheap; inexpensive

high; tall; expensive

low (position, content, quality, etc.); short (height)

heavy; weighty

light (i.e. not heavy)

weak; frail; delicate

strong; powerful; mighty

old (things, not person); ancient

new; recent; modern

few; a little; scarce

many; numerous

short

long

fat; thick

thin; slender; fine

small; little; tiny

big; large; great