The /f/ sound is spelled with <f>, <ff>, <gh> in rough or <ph> in phone. The /m/ sound is spelled <m> or <mm>.
The contrast is between a voiceless labio-dental fricative and a voiced bilabial nasal continuant. It is not usually a problem.
Taboo word pairs include fart/mart and fuck/muck. Occasionally mucking is used in fiction as a stand-in for fucking, as in "What do you mucking well think you're doing?".
Interesting pairs include:
faster master
felon melon
ferret merit
fighter mitre
firmer murmur
fortification mortification
funny money
refined remind
suffer summer
The mean density value is 3.4%. The list makes 205 semantic distinctions, a loading of 54%.
beef beam beefing beaming beefs beams brief bream briefs breams buff bum buffing bumming buffs bums caff cam caffs cams calf calm cf cm chaff charm chaffing charming clef Clem coffer comma coffers commas Crieff cream cuff come cuffing coming cuffs comes Cuffley comely defer demur deferred demurred deferring demurring defers demurs defies demise differ dimmer differs dimmers duffer dumber electrocardiograph electrocardiogram elephant element elephants elements elf elm F M fa ma fa mar fable Mabel face mace faces maces fad mad faddy Maddy fade made fade maid fades maids fairy Mary fag mag fags mags faggot maggot faggots maggots fail mail failed mailed failing mailing fails mails fail male fails males fain main fain Maine fair mare fairs mares fake make fakes makes faking making fall mall falls malls fall maul falling mauling falls mauls fallow Mallow fame maim famed maimed fan man fans mans fanned manned fanning manning fancies manses far ma far mar fare mare fares mares farrow marrow farrows marrows fart mart farts marts fast mast fasts masts faster master fat mat fats mats fatted matted fatting matting fat Matt fate mate fated mated fating mating fates mates fatter matter faugh maw fault malt faulted malted faulting malting faults malts faun morn fauns morns faun mourn fauns mourns fawn morn fawns morns fawning morning fawn mourn fawns mourns fawned mourned fawning mourning Fawley Morley fear mere fears meres feat meat feats meats feat mete feats metes fed Med fee me feed mead feeds meads feet meat feet mete feign main feigns mains feign Maine fellow mellow fellows mellows felon melon felons melons felt melt fen men fend mend fended mended fending mending fends mends fender mender fenders menders ferret merit ferreted merited ferreting meriting ferrets merits ferry merry fête mate fêted mated fêting mating fêtes mates fettle metal feud mewed few mew fey May fickle mickle fiddle middle fiddles middles fiddling middling fiddled middled fidget midget fidgets midgets fie my fiery miry fight might fight mite fights mites fighter mitre fighters mitres filch milch file mile files miles filed mild fill mill filled milled filling milling fills mills fillet millet filly Millie find mind finding minding finds minds finder minder finders minders fine mine fines mines fining mining fined mined finer miner fir myrrh fire mire fired mired fires mires firing miring firmer murmur Firth mirth fissile missile fission mission fist missed fisdt mist fists mists fix mix fixed mixed fixes mixes fixing mixing fixture mixture fixtures mixtures fizzle mizzle fizzled mizzled fizzling mizzling foal mole foals moles foaled mould fob mob fobbed mobbed fobbing mobbing fobs mobs foe mo foe mow foes mows foil moil foiled moiled foiling moiling foils moils foist moist fold mould folded moulded folding moulding folds moulds folder moulder folders moulders folk moke folks mokes folly Molly food mood foods moods fop mop fops mops for maw fore maw four maw fours maws for more fore more four more force Morse ford Maud foreman Mormon Forfar former fortify mortify fortified mortified fortifies mortifies fortifying mortifying fortification mortification fortifications mortifications fosse moss fosses mosses found mound founds mounds fount mount founts mounts fountain mountain fountains mountains fox mocks fuck muck fucked mucked fucking mucking fucks mucks fuddle muddle fuddled muddled fuddles muddles fuddling muddling fug mug fugs mugs fuggy muggy fuggier muggier fuggiest muggiest fumble mumble fumbled mumbled fumbles mumbles fumbling mumbling funk monk funks monks funky monkey funny money fur myrrh fuse mews fuse muse fused mused fuses muses fusing musing fuss muss fussed mussed fusses musses fussing mussing fusty musty fuzzy muzzy fuzzier muzzier fuzziest muzziest gaffer gamma gaffers gammas Geoff gem half harm hoof whom huff hum huffing humming huffs hums huffed hummed jiffy Jimmy jiffies jimmies life lime loaf loam muff mum oaf ohm oafs ohms offend amend offended amended offending amending offends amends phase Mays phase maize phase maze phased mazed phases mazes phone moan phoned moaned phones moans phoning moaning phut mutt preface premise prefaced premised prefaces premises prefacing premising Prof prom radiograph radiogram reef ream refined remind rife rhyme riff rim roof rheum roof room roofing rooming roofs rooms rough rum rougher rummer roughest rummest roughage rummage safe same safeness sameness scruff scrum scuff scum siphon Simon skiff skim slough slum sloughing slumming sloughed slummed sloughs slums sough some sough sum soughing summing soughs sums sphere smear spheres smears Stafford stammered suffer summer suffered summered suffering summering suffers summers Taffy tammy Taffies tammies thief theme toff Tom toffee Tommy toughie tummy toughies tummies turf term turfing terming wharf warm whiff whim whiffs whims woof womb woofs wombs