unshakably

absolutely assuredly certainly clearly definitely evidently indeed inevitably inexorably plainly undoubtedly unquestionably

admittedly beyond doubt beyond shadow of doubt come what may conclusively decidedly distinctly doubtlessly explicitly fixedly for certain indubitably infallibly irrefutably manifestly nothing else but positively rain or shine to be sure unequivocally unerringly unfailingly unmistakably with certainty without fail

doubtfully dubiously indefinite indefinitely questionably vaguely

uncertain