Here are the words in the CommonWords database on this website with [f] spelled <ph>:atmosphere, elephant, emphasis, emphasize, geography, graph, hemisphere, nephew, nymph, orphan, paragraph, phase, phenomenon, Philadelphia, Philippines, philosopher, philosophy, phoebe, phone, photograph, phrase, physical, physician, physics, prophecy, prophet, Ralph, sphere, sulphur, telegraph, telephone, triumph
Words with [f] spelled <gh>:cough, enough, laugh, laughter, rough, roughly, tough
In the following list of words with [f] spelled <f> I’ve left out words that start with <f> due to space limitations. You can find them easily in your dictionary, or by going to the CommonWords database, clicking on the CommonWords table, and searching on “Word begins with f”: afar, afraid, Africa, after, afternoon, afterward, afterwards, artificial, awful, awfully, beautiful, beef, befall, before, belief, benefit, breakfast, brief, briefly, butterfly, California, careful, carefully, certificate, cheerful, cheerfully, chief, chiefly, circumference, comfort, comfortable, comfortably, confederate, confer, conference, confess, confession, confide, confidence, confident, confiding, confine, confirm, confirmed, conflict, confound, confront, confuse, confusion, craft, cupful, deaf, defeat, defect, defend, defense, defiance, define, definite, definitely, defy, delightful, dignified, doubtful, draft, dreadful, drift, dwarf, enforce, gift, golf, goof, graceful, grandfather, grateful, gratify, grief, gulf, handful, handkerchief, helpful, henceforth, hereafter, herself, himself, hoof, housewife, identify, if, infant, infantry, infection, inferior, infinite, inflict, influence, inform, information, interfere, interference, itself, justify, knife, leaf, left, life, lifetime, lift, loaf, lofty, magnificent, manifest, manufacture, manufacturer, mischief, misfortune, modify, myself, Norfolk, notify, oft, old-fashioned, outfit, overflow, Oxford, Pacific, pacific, painful, peaceful, perfect, perfection, perfectly, perform, performance, perfume, pitiful, platform, plentiful, poof, powerful, preface, prefer, preference, prefix, profess, profession, professional, professor, profit, profitable, profound, proof, qualified, qualify, reef, refer, reference, reflect, reflection, reform, refrain, refresh, refreshment, refrigerator, refuge, refusal, refuse, relief, rifle, roof, sacrifice, safe, safeguard, safely, safety, San Francisco, satisfaction, satisfactory, satisfy, scarf, scientific, self, selfish, shaft, shelf, shift, sift, significance, significant, signify, skillful, sofa, soft, softly, software, specific, stifle, strife, successful, successfully, sulfur, surface, swift, swiftly, teaspoonful, terrific, terrify, testify, thankful, thereafter, therefore, thereof, thief, thoughtful, thoughtfully, transfer, transform, trifle, trifling, turf, twelfth, uncomfortable, unfit, unfold, unfortunate, unfortunately, uniform, uplift, useful, warfare, watchful, waterfall, welfare, wharf, wherefore, wife, wolf, wonderful, yourself, youthful
And for good measure, words with [f] spelled <ff>:affair, affect, affection, affectionate, affirm, afford, bluff, buffalo, buffet, cliff, coffee, cuff, differ, difference, different, differently, difficult, difficulty, effect, effective, efficiency, efficient, effort, indifference, indifferent, Jefferson, off, offend, offense, offensive, offer, offering, office, officer, official, offspring, puff, ruffle, sheriff, sniff, staff, stiff, stiffly, stuff, suffer, suffering, suffice, sufficient, sufficiently, suffix, suffrage, tariff, traffic
If you need more words, you can go to the Lexis Database on this website. Then click on the Words table and fill in the search strings for “Word contains” with f, ff, gh, ph, separately one after the other. You will get a lot of false hits here because, for instance, <gh> doesn’t always spell [f], and you’ll have to pick out the cases in which it does. But you will surely get a lot more words that way because Lexis is a much larger database than CommonWords.