Synonyms for certainly

absolutely, assuredly, confidently, decisively, definitely, doubtless, doubtlessly, for sure, incontestably, incontestably., incontrovertibly, indeed, indisputably, indubitably, inescapably, inevitably, of course, positively, precisely, surely, truly, uh-huh, unambiguously, unarguably, unassailably, unavoidably, undeniably, undoubtably, undoubtedly, unequivocally, unescapably, unquestionably, veritably, without question, yea, yeah, yep, yes, yup