The spelling of /p/ is always either <p> or <pp>. The /n/ sound is spelled <n>, <nn> or <gn> in a few words such as gnaw.
Since /n/ can be syllabic or consonantal, there is a problem with such pairs as crisp/christen, lisp/listen and lisping/listening, which differ in syllable count, although the computer algorithm includes them as minimal.
The contrast is between a voiceless plosive and a voiced nasal continuant well apart in the mouth. The only problems for learners might occur with speakers of languages which do not allow post-vocalic clusters, who might have trouble with pairs such as skipped/skint.
The only pair involving any taboo words is cupped/cunt.
Interesting pairs include:
The mean density value is 2.7%. The list makes 300 semantic distinctions, a loading of 53%.
aped ain't appeal anneal appealed annealed appealing annealing appeals anneals apples annals appoint anoint appointed anointed appointing anointing appoints anoints appointment anointment appointments anointments apt ant Bacup bacon beep bean beeps beans beep been burp Bern burped burnt burping burning burps burns burp Bern cap can capped canned capping canning caps cans cap Cannes cape Cain cape cane caped caned capes canes capped cant captor canter captors canters carp Calne carp khan carpal carnal carped can't chapel channel chapels channels chip chin chipped chinned chips chins chirp churn chirped churned chirping churning chirps churns clap clan claps clans coop coon coops coons cop con copped conned copping conning cops cons cope Colne cope cone coped coned coping coning copes cones cops cons copse cons copy Connie Corp corn crepe crane crisp christen crisping christening croup croon cupped cunt cupping cunning deception dissension deceptions dissensions deep dean dip din dipped dinned dipping dinning dips dins dipped dint dipper dinner dippers dinners doped don't drape drain draped drained draping draining drapes drains dupe dune dupes dunes epoch Enoch flap flan flaps flans flipped flint gallop gallon galloped gallant Gallup gallon gape gain gaped gained gaping gaining gapes gains gawped gaunt grape grain grapes grains grip grin gripped grinned gripping grinning grips grins grippe green grope groan groped groaned groping groaning gropes groans grope grown gyp gin gypping ginning gyps gins gyp djinn hep hen hop Hon hope hone hoped honed hoping honing hopes hones jape Jane jeep Jean jeep gene jeeps genes keep keen keeping keening keeps keens keeper keener kept Kent kip kin kopje Connie leap lean leaping leaning leaps leans leapt leant leapt lent leapt Lent leopard Leonard lip Lynn lipped lint lisp listen lisping listening loop loon loops loons loopy loony lope loan loped loaned loping loaning lopes loans map man mapped manned mapping manning maps mans maps manse mope moan moped moaned moping moaning mopes moans mope mown nappy nanny nappies nannies nippy ninny nope known op on operable honourable opus onus P knee P's knees pack knack packs knacks packer knacker packers knackers pail nail pails nails pair ne'er pale nail paled nailed paling nailing pales nails pap pan pare ne'er park nark parked narked parking narking parks narks pat gnat pats gnats pat Nat patter natter pattered nattered pattering nattering patters natters patty natty pause gnaws pave knave paves knaves pave nave paves naves paw gnaw pawed gnawed pawing gnawing paws gnaws paw nor pax knacks pay nay pay n_ee pay neigh paying neighing pays neighs paid neighed pea knee peas knees peace Nice peace niece peal kneel pealed kneeled pealing kneeling peals kneels peal Neil pear ne'er pease knees peat neat peck neck pecked necked pecking necking pecks necks pee knee pees knees peed knead peed need peel kneel peeled kneeled peeling kneeling peels kneels peel Neil peer near peered neared peering nearing peers nears pelt knelt people penal pep pen pepped penned pepping penning peps pens peps pence pest nest pester Nestor pestle nestle pestled nestled pestles nestles pestling nestling pests nests pet net pets nets petted netted petting netting pet nett petal nettle petaled nettled petals nettles Pete neat peter neater pew knew pew new pews news pewter neuter pi nigh pick nick picked nicked picking nicking picks nicks picks nix pickers knickers pickle nickel pickled nickelled pickles nickels pie nigh piece Nice piece niece pieces nieces pier near piers nears pill nil pine nine pines nines pinny nippy pinnies ninnies pip pin pipped pinned pipping pinning pips pins pipe pine piped pined piping pining pipes pines piped pint pit knit pitted knitted pitting knitting pits knits pit nit pits nits pitch niche pitches niches pitied knitted pock knock pocked knocked pocks knocks pod nod podded nodded podding nodding pods nods poise noise poised noised poises noises poising noising pole knoll poles knolls poll knoll polls knolls ponce nonce ponces nonces poodle noodle poodles noodles pooh gnu poop noon pops ponce porch nautch porches nautches pore gnaw pored gnawed pores gnaws pore nor port nought ports noughts pose knows pose nos pose nose posed nosed poses noses posing nosing posh nosh posy nosey posies noses pot knot pots knots potted knotted potting knotting pot not potable notable potation notation potations notations pothole knothole potholes knotholes potion notion potions notions potty knotty pottier knottier pottiest knottiest pour gnaw poured gnawed pours gnaws pour nor pout knout pouts knouts pox knocks preceptor precentor preceptors precentors P's knees pub nub pubs nubs pun none pun nun puns nuns pup pun puppet punnet puppets punnets purse nurse pursed nursed purses nurses pursing nursing putt nut putts nuts putted nutted putting nutting puttee nutty puzzle nuzzle puzzled nuzzled puzzles nuzzles puzzling nuzzling pylon nylon pylons nylons pyre nigher pyx nicks pyx nix quip quin quips quins quips quince rap ran rape rain raped rained rapes rains raping raining rape reign raped reigned raping reigning rapes reigns rape rein rapes reined rapes reins raping reining rapier rainier rapped rant rapt rant rep Rennes repp Rennes rep wren repp wren ripe Rhine rips rinse rope roan ropes roans sceptre centre sceptered centred sceptres centres seep scene seeps scenes seep seen sepia senior Sept cent Sept scent Sept sent sheep sheen ship shin shipped shinned shipping shinning ships shins shop shone sip sin sipped sinned sipping sinning sips sins sips since skip skin skipped skinned skipping skinning skips skins skipped skint soap sown soppier Sonia soup soon spake snake spare snare spared snared spares snares sparing snaring speak sneak speaking sneaking speaks sneaks speaker sneaker speakers sneakers spear sneer speared sneered spearing sneering spears sneers spick snick spied snide Spode snowed spook snook spooks snooks spore snore spores snores sport snort sported snorted sporting snorting sports snorts spot snot spotty snotty spottier snottier spottiest snottiest spout snout spouts snouts step Sten steppe Sten stepping Steyning sup son sups sons sup sun supped sunned supping sunning sups suns super sooner swap swan swapped swanned swapping swanning swaps swans swipe swine swoop swoon swooped swooned swooping swooning swoops swoons tap tan tapped tanned tapping tanning taps tans taped taint tip tin tipped tinned tipping tinning tips tins tipped tint tope tone toped toned toping toning topes tones topi Tony topic tonic topics tonics troop Troon troupe Troon tup tonne tup tun type tine type Tyne up un updated undated upon Anon vapour vainer warp warn warped warned warping warning warps warns warp worn weep wean weeping weaning weeps weans wept went whip whin whip win whips wins whipping winning whippings winnings whipping-post winning-post whipping-posts winning-posts whippy whinny whips wince whop wan whopped want whopper wanner wipe whine wiped whined wiping whining wipes whines wipe wine wiping wining wipes wines wiper whiner wipers whiners wrap ran wrapped rant
John Higgins, Shaftesbury, January 2010.