Adverbs starting with the letter C are listed here. Many kinds of adverbs are included which can be useful for creating interesting sentences.
ca., cagily, cajolingly, calculatingly, callously, calmly, calumniously, candidly, cannily, canonically, cantankerously, capably, capriciously, captiously, captivatingly, carefully, carelessly, carnally, casually, catalytically, catastrophically, categorically, caudal, caudally, causally, caustically, cautiously, cavalierly.
ceaselessly, centennially, centrally, cerebrally, ceremonially, ceremoniously, certainly.
chaotically, characteristically, charily, charitably, charmingly, chastely, chattily, cheap, cheaper, cheaply, cheekily, cheerfully, cheerily, cheerlessly, chemically, chiefly, childishly, chintzily, chirpily, chivalrously, chock, chorally, chromatically, chromatographically, chronically, chronologically, churlishly.
circa, circularly, circumspectly, circumstantially, civilly.
clairaudiently, clammily, clamorously, clannishly, classically, clean, cleanly, clear, clearly, cleverly, climatically, clinically, cliquishly, clockwise, close, closely, closer, closest, cloyingly, clumsily.
coarsely, coastward, coastwise, coaxingly, cod, cogently, cognitively, coherently, cohesively, coincidentally, coincidently, cold, coldly, collect, collectedly, collectively, colloidally, colloquially, combatively, comfortably, comfortingly, comically, commendable, commensally, commercially, commonly, communally, compactly, comparably, comparatively, compassionately, compatibly, competently, competitively, complacently, complainingly, completely, complexly, composedly, comprehensively, compulsively, compulsorily, computationally, con, concavely, concededly, conceitedly, conceivably, conceptually, concernedly, concisely, conclusively, concretely, concurrently, condescendingly, conditionally, confessedly, confidentially, confidently, confidingly, conformably, confoundedly, confusedly, confusingly, congenially, conically, conjecturally, conjointly, conjugally, connubial, consanguineously, conscientiously, consciously, consecutive, consecutively, consequentially, consequently, conservatively, considerably, considerately, consisently, consistently, consolingly, conspicuously, constantly, constitutionally, constrainedly, constructively, consummately, contagiously, contemptibly, contemptuously, contentedly, contextually, continentally, continually, continuously, contractually, contradictorily, contrarily, contrariwise, contrastingly, contritely, controversially, contumaciously, contumeliously, conveniently, conventionally, conversationally, conversely, convexly, convincingly, convivially, convulsively, cool, coolly, cooperatively, coordinately, copiously, coquettishly, cordially, correctly, correlatively, correspondingly, corruptedly, corruptly, cortically, cosily, cosmetically, coterminously, counter, counteractively, counterclockwise, counterintuitively, courageously, course, courteously, covertly, covetously, cowardly, coyly, cozily.
craftily, crazily, creakily, creakingly, creatively, credibly, creditably, credulously, criminally, crisply, crisscross, critically, crookedly, crossly, crosstown, crossways, crosswise, crucially, crudely, cruelly, crushingly, cryptically, cryptographically.
culpably, culturally, cumulatively, cunningly, curiously, currently, currishly, cursedly, cursively, cursorily, curtly, curvaceously, cussedly, customarily, cutely, cuttingly.
cynically, cytophotometrically, cytoplasmically.
There are lots of other useful posts on Adverb1.com to explore which are similar to the above C adverbs list but which start with different letters for example.