Observed adverbs are provided in this article. The words listed here are commonly found along with the verb observed in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb OBSERVED.
accidentally, accordingly, accurately, actually, acutely, anciently, annually, anxiously, apparently, appropriately, aptly, astutely, attentively, beautifully, briefly, calmly, carefully, carelessly, casually, cautiously, certainly, chiefly, clearly, clinically, closely, coldly, commonly, conscientiously, consistently, constantly
continually, continuously, coolly, correctly, critically, curiously, currently, cynically, daily, devoutly, diligently, directly, distinctly, drily, dryly, duly, early, easily, emphatically, empirically, equally, especially, evidently, exactly, excellently, experimentally, expressly, facetiously, faithfully, famously
finally, finely, formerly, frequently, fully, generally, gravely, grimly, habitually, happily, hardly, immediately, imperfectly, incidentally, independently, infrequently, initially, instantly, invariably, inviolably, judiciously, justly, keenly, lately, laughingly, literally, loyally, mainly, merely, meticulously
microscopically, mildly, minutely, mostly, narrowly, naturally, nearly, necessarily, newly, nicely, normally, objectively, occasionally, ordinarily, originally, partially, particularly, perceptively, perfectly, perpetually, personally, pertinently, plainly, pleasantly, pointedly, practically, presently, previously, primarily, probably
properly, publicly, punctiliously, punctually, quickly, quietly, rarely, readily, really, recently, regularly, reliably, religiously, repeatedly, reverently, rightly, rigidly, rigorously, routinely, ruefully, sacredly, sadly, sagaciously, sagely, sarcastically, scarcely, scrupulously, secretly, separately, shortly
shrewdly, significantly, silently, similarly, simply, simultaneously, smilingly, solemnly, specially, strictly, studiously, subsequently, successfully, suddenly, sufficiently, systematically, thoughtfully, traditionally, truly, typically, unfrequently, uniformly, universally, usually, visually, widely, wisely, wittily, wryly
Hope this word list had the observed adverb you were looking for. In addition to adverbs used with observed, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.