Adjectives: restricted or special -ly form

Adjective	Flat adverb (normal)	-ly form	Status / Meaning
close	close	closely	✔ exists but meaning changes (“carefully”)
deep	deep	deeply	✔ exists but usually figurative / intensity
fast	fast	fastly	❌ obsolete / not used
far	far	farly	❌ does not exist
first	first	firstly	✔ exists mainly in enumerations
hard	hard	hardly	✔ exists but different meaning (“almost not”)
high	high	highly	✔ exists but usually intensifying (“very / greatly”)
last	last	lastly	✔ exists mainly in enumerations
late	late	lately	✔ exists but different meaning (“recently”)
long	long	longly	❌ obsolete / not used
main	main	mainly	✔ exists but formal / “chiefly” meaning
mere	mere	merely	✔ exists but formal / limited use
near	near	nearly	✔ exists but meaning “almost”
next	next	nextly	❌ does not exist
quick	quick	quickly	✔ exists; flat form informal
right	right	rightly	✔ exists but formal / evaluative meaning
slow	slow	slowly	✔ exists; flat form informal, -ly formal
sharp	sharp	sharply	✔ exists but meaning changes (suddenly / precisely)
soon	soon	soonly	❌ does not exist
straight	straight	straightly	❌ very rare / archaic
utter	utter	utterly	✔ exists but lexicalized, not compositional
wrong	wrong	wrongly	✔ exists but formal / legal sense