for certain

肯定地；确凿地

footnote, footpath, footplate, footprint, footsie, footsore, footstep, footstool (also stool), footway, footwear, footwork, fop, foppish, for, for (the) purpose of, for a moment, for a while, for ages, for all that, for another two days, for ever, for example, for fear of, for fear that, for good, for instance, for lack of, for life, for long, for one thing, for one thing...for another, for one's sake, for sale, for short, for some reason, for sure, for the best, for the better, for the first time, for the future,