Some original adverbs: seldom, always, yesterday, today, tomorrow, here, there, never, well.

Adverbs from adjectives

Examples
possibly	humbly	thinly	gladly
sheepishly	slowly	loudly	usually
slavishly	clearly	sincerely
silently	normally	finally	nicely
kindly	harshly	honestly	correctly
rightly	beautifully	mercifully	helpfully
wonderfully	frequently	immediately	coldly
dully	forcefully	hatefully	painfully
smartly	proudly	sadly	badly
madly	fairly	hopefully	sorrowfully
dryly	largely	wisely	fully
bravely	generally	leisurely	boldly

Examples
gaily	lazily	readily	happily
angrily	busily	merrily	hungrily
wearily	heavily

Examples
reasonably	desirably	preferably	tolerably
honorably	suitably	profitably	fashionably
favorably	plausibly	forcibly	sensibly

Examples
Adjective	Adverb
true	truly
due	duly
whole	wholly