The spelling of /p/ is always either <p> or <pp>. The /r/ sound is spelled <r> or <rr>, or sometimes <wr> initially. Since /r/ cannot occur finally, all the contrasts are initial or intervocalic.
The contrast is between a voiceless plosive and a voiced retroflex continuant, well apart in the mouth. It causes no problems.The only mildly taboo word pairings are pee/re and peed/read.
Interesting pairs include:
papaya pariah passion ration
The mean density value is 2.1%. The list makes 183 semantic distinctions, a loading of 49%.
appears arrears canopy cannery canopies canneries copy corrie copies corries corpus chorus diaper direr gawping goring happy harry happier harrier hopper horror hoppers horrors keeping keyring kopje corrie kopjes corries oppose arose P re pa rah pace race paced raced paces races pacing racing pack rack packed racked packing racking packs racks pack wrack packet racket packets rackets pact racked paddled raddled page rage paged raged pages rages paging raging pah rah paid raid pail rail pails rails pain rain pained rained paining raining pains rains pain reign pained reigned paining reigning pains reigns pain rein pained reined paining reining pains reins pair rare pairing raring pale rail paled railed paling railing palings railings pallid rallied pally rally Pam ram pan ran pane rain panes rains pane reign panes reigns pane rein panes reins pang rang panned rand pant rant panted ranted panting ranting pants rants pap rap papaya pariah papayas pariahs papist rapist papists rapists par rah pare rare parr rah passion ration passions rations paste raced pat rat pats rats patted ratted patting ratting pate rate pates rates patter ratter patters ratters patty ratty pause roars pave rave paved raved paves raves paving raving paw raw paw roar pawed roared paws roars pax racks pay ray paid rayed paying raying pays rays pay re payment raiment pays raise pays raze pea re peach reach peached reached peaches reaches peaching reaching peak reek peaked reeked peaking reeking peaks reeks peak wreak peaked wreaked peaking wreaking peaks wreaks peal reel pealed reeled pealing reeling peals reels pear rare peck wreck pecked wrecked pecking wrecking pecks wrecks pecker wrecker peckers wreckers pecks Rex pee re peed read peed reed peek reek peeked reeked peeking reeking peeks reeks peek wreak peeked wreaked peeking wreaking peeks wreaks peel reel peeled reeled peeling reeling peels reels peeper reaper peepers reapers peer rear peered reared peering rearing peers rears peer rhea peers rheas peeve reeve peeves reeves peke reek pekes reeks peke wreak pekes wreaks Peking reeking Peking wreaking pen Rennes pen wren pens wrens penal renal pending rending penned rend pep rep peps reps pest rest pests rests pest wrest pests wrests pestle wrestle pestles wrestles petard retard petards retards pests rests peter Rita pi rye pi wry pick rick picked ricked picking ricking picks ricks pickets rickets piddle riddle piddled riddled piddles riddles piddling riddling pie rye pie wry pied ride pied Ryde pier rear piers rears pier rhea piers rheas pies rise piffle riffle piffled riffled piffles riffles piffling riffling pig rig pigged rigged pigging rigging pigs rigs pike Reich pikes Reichs pile rile piled riled piles riles piling riling pill Rhyl pill rill pills rills pine Rhine pined rind ping ring pinged ringed pinging ringing pings rings ping wring pinging wringing pings wrings pink rink pinks rinks pipe ripe piper riper pique reek piqued reeked piques reeks piquing reeking pique wreak piqued wreaked piques wreaks piquing wreaking pis rise pissed wrist pit writ pits writs pitch rich pitches riches pitcher richer poach roach poaches roaches pock roc pocks rocs pock rock pocked rocked pocks rocks pocket rocket pocketed rocketed pocketing rocketing pockets rockets pod rod pods rods polar roller pole role poles roles pole roll polled rolled polling rolling poles rolls poll role polls roles poll roll polled rolled polling rolling polls rolls pom rhomb poms rhombs pomp romp ponder Rhondda pone roan pones roans poof roof poofs roofs pooh rue pool rule pooled ruled pooling ruling pools rules Pope rope Popes ropes pore raw pore roar pored roared poring roaring pores roars porous porpoise port wrought pose roes pose rose poses roses pose rows posies roses post roast posted roasted posting roasting posts roasts poster roaster posters roasters posy rosy pot rot pots rots potted rotted potting rotting potation rotation potations rotations potter rotter potters rotters pouffe roof pouffes roofs pound round pounded rounded pounding rounding pounds rounds pounder rounder pounders rounders pour raw pour roar poured roared pouring roaring pours roars pout rout pouted routed pouting routing pouts routs pox rocks pox rocs pub rub pubs rubs puck ruck pucks rucks puddle ruddle puddled ruddled puddles ruddles puddling ruddling puff rough puffed roughed puffing roughing puffs roughs puff ruff puffed ruffed puffing ruffing puffs ruffs pug rug pugs rugs pump rump pumps rumps pun run punning running puns runs punt runt punts runts putt rut putts ruts putted rutted putting rutting puttied rutted Pyle rile pyre wrier pyx ricks soppy sorry soppier sorrier soppiest sorriest warping warring
John Higgins, Shaftesbury, January 2010.