A list of regular adverbs - since it is not always clear which adjectives can easily be turned into adverbs.
I have set those words in boldface that are also included in the list of possible flat adverbs.
The list is taken from List of commonly used adverbs
"Remember that adverbs describe or indicate the degree of action verbs, adjectives, or other adverbs."
abnormally, absent-mindedly, accidentally, actually, adventurously, afterwards, almost, annually, anxiously, arrogantly, awkwardly,
bashfully, beautifully, bitterly, bleakly, blindly, blissfully, boastfully, boldly, bravely, briefly, brightly, briskly, broadly,
busily, calmly, calmly, carefully, carelessly, cautiously, certainly, cheerfully, clearly, cleverly, closely, coaxingly, colourfully,
commonly, continually, coolly, correctly, courageously, crossly, cruelly, curiously, daily, daintily, dearly, devceivingly, deeply,
defiantly, deliberately, delightfully, diligently, dimly, doubtfully, dreamily, easily, excitedly, extremely, fairly, faithfully,
famously, far, fast, fatally, ferociously, fervently, fiercely, fondly, foolishly, fortunately, frankly, frantically,
freely, frenetically, frightfully, fully, furiously, generally, generously, gently, gladly, gleefully, gracefully, gratefully,
greatly, greedily, happily, hastily, healthily, heavily, helpfully, helplessly, highly, honestly, hopelessly, hourly,
hungrily, immediately, innocently, inquisitively, instantly, intensely, intently, interestingly, inwardly, irritably, jaggedly,
jealously, jovially, joyfully, joyously, jubilantly, judgmentally, justly, keenly, kiddingly, kindheartedly, kindly, knavishly,
knowingly, knowledgeably, kookily, lazily, less, lightly, likely, limply, lively, loftily, longingly, loosely, loudly,
lovingly, loyally, madly, majestically, meaningfully, mechanically, merrily, miserably, mockingly, monthly, more, mortally,
mostly, mysteriously, naturally, nearly, neatly, nervously, never, nicely, noisily, not, obediently, obnoxiously, oddly,
offensively, officially, often, only, openly, optimistically, overconfidently, painfully, partially, patiently, perfectly,
physically, playfully, politely, poorly, positively, potentially, powerfully, promptly, properly, punctually, quaintly,
queasily, queerly, questionably, quicker, quickly, quietly, quirkily, quizzically, randomly, rapidly, rarely, readily,
really, reassuringly, recklessly, regularly, reluctantly, repeatedly, reproachfully, restfully, righteously, rightfully, rigidly,
roughly, rudely, safely, scarcely, scarily, searchingly, sedately, seemingly, seldom, selfishly, separately, seriously,
shakily, sharply, sheepishly, shrilly, shyly, silently, sleepily, slowly, smoothly, softly, solemnly, solidly,
sometimes, soon, speedily, stealthily, sternly, strictly, successfully, suddenly, supposedly, surprisingly, suspiciously, sweetly,
swiftly, sympathetically, tenderly, tensely, terribly, thankfully, thoroughly, thoughtfully, tightly, tomorrow, too, tremendously,
triumphantly, truly, truthfully, ultimately, unabashedly, unaccountably, unbearably, unethically, unexpectedly, unfortunately,
unimpressively, unnaturally, unnecessarily, upbeat, upright, upside-down, upward, urgently, usefully, uselessly, usually,
utterly, vacantly, vaguely, vainly, valiantly, vastly, verbally, very, viciously, victoriously, violently, vivaciously,
voluntarily, warmly, weakly, wearily, well, wetly, wholly, wildly, willfully, wisely, woefully, wonderfully, worriedly,
wrongly, yawningly, yearly, yearningly, yesterday, yieldingly, youthfully, zealously, zestfully, zestily
Adverbs I feel are also being used a lot and missing in the list:
abruptly, accordingly, adequately, admittedly, allegedly, assumedly, assumably, automatically, basically, completely,
currently, curtly, doubtlessly, entirely, exceedingly, eventually, finally, harshly, haughtily, historically, literally,
meekly, necessarily, obsessively, particularly, relatively, remotely, stiffly, technically, totally, vigorously
(to be continued)
Adjectives that are used a lot and whose adverbs are missing in the list -
but which I feel are either indeed hardly used as adverbs or at least not as an adverb with -ly:
awesome(ly), cute(ly), small, tiny, weird(ly)
Are the following adjectives (commonly) used as adverbs?
bizarre, blurry, bulky, compulsory, evil, extraordinary, feminine, fond, inconspicuous, jocular, mandatory, obscure, ominous, paltry, plausible, preposterous,
puny, ridiculous, silly, stupid, tidy, vindictive, witty
(In what list do they belong?)
A Canadian once expressed his anger about a programme by saying: "This is stupidly and needlessly complicated!"
So it seems that "stupidly" is possible, but I don't think I have come across it very often. Also, for my taste,
the sentence sounds rather bulky.