The /f/ sound is spelled with <f> or <ph> in phone. The /h/ sound is spelled <h>.
The contrast is between a labio-dental fricative and a glottal fricative, both voiceless. It is not usually a problem even though there is some acoustic similarity.
Taboo word pairs include fart/heart.
The contrast only occurs initially apart from in the compound words overfed/overhead. Other interesting pairs include:
forehead horrid (using a rather archaic pronunciation of forehead)
The mean density value is 3.7%. The list makes 119 semantic distinctions, a loading of 52%.
fa ha faced haste fact hacked fad had fairy hairy fag hag fags hags fail hail failed hailed failing hailing fails hails fair Herr fair hair fairs hairs fair hare fairs hares fake hake fall hall falls halls fall haul falling hauling falls hauls fallow hallow falter halter falters halters fang hang fanned hand fare hair fares hairs fare hare fared hared faring haring fares hares farm harm farmed harmed farming harming farms harms farrier harrier farriers harriers farrow harrow farrowed harrowed farrowing harrowing farrows harrows fart hart farts harts fart heart farted hearted farts hearts fat hat fats hats fate hate fates hates fatter hatter faugh haw faugh hoar fault halt faulted halted faulting halting faults halts faun horn fauns horns fawn horn fawns horns fawned horned fawning horning favour haver favouring havering favours havers Fawley Horley fear hear fearing hearing fears hears feather heather fed head fee he feed heed feeding heeding feeds heeds feeler healer feelers healers feet heat fell hell fells hells felled held felon Helen fem hem fen hen fens hens fence hence fern Herne f�te hate f�ted hated f�ting hating f�tes hates feud hewed few Hugh fewer hewer fey hay fie hi fie high fight height fights heights filly hilly find hind finds hinds fir her firs hers fire higher fire hire fired hired fires hires firing hiring fist hissed five hive fives hives fix hicks foal hole foaling holing foals holes foaled holed foal whole foals wholes foaled hold foam home foaming homing foams homes foamed homed foamy homey fob hob fobs hobs foe ho foe hoe foes hoes fog hog fogged hogged fogging hogging fogs hogs foist hoist foisted hoisted foisting hoisting foists hoists fold hold folding holding folds holds folder holder folders holders folks hoax follow holloa follow hollow followed hollowed following hollowing follows holloas folly holly fop hop fops hops for haw fore haw four haw fours haws for hoar fore hoar four hoar force hoarse force horse forces horses forcemeat horsemeat ford hawed ford hoard forded hoarded fording hoarding fords hoards ford horde fords hordes forehead horrid fork hawk forked hawked forking hawking forks hawks form haulm forty haughty foul howl fouled howled fouling howling fouls howls fouler howler found hound founded hounded founding hounding founds hounds fowl howl fowls howls fowler howler fowlers howlers fox hocks fuddle huddle fuddled huddled fuddles huddles fuddling huddling fug hug fugs hugs fumble humble fumbled humbled fumbles humbles fumbling humbling fumbler humbler fun Hun funk hunk funks hunks funny honey fur her furs hers furl hurl furled hurled furling hurling furls hurls fuse hews fussy hussy overfed overhead phase haze phased hazed phases hazes phasing hazing phone hone phoned honed phones hones phoning honing phooey hooey phut hut
Credit: John Higgins