The /ɒ/ vowel is usually spelled <o> but we also find <a> after <w> in wander. The /ʌ/ vowel is normally spelled <u>, but we also find <o> in colour and <ou> in tough.
This contrast is between two short vowels, fairly close in tongue positions. It is a recognised problem for Dutch, Danish and French speakers, but not in general for speakers of 5-vowel languages like Italian or Swahili.
The only taboo word pairs are bomb/bum, cont./cunt and fox/fucks.
Interesting pairs include:
solid sullied warrior worrier
The density value is 4.62%. The pairs make 155 semantic contrasts, giving a loading of 48.1%.
amok amuck begone begun blonder blunder body buddy bodied budded bodies buddies bog bug bogged bugged bogging bugging bogs bugs boggy buggy bomb bum bombed bummed bombing bumming bombs bums bonkers bunkers Bonn bun bonny bunny borrow burrow borrowed burrowed borrowing burrowing borrows burrows boss bus bossed bused bosses buses bossing busing box bucks choc chuck chocked chucked chocking chucking chocks chucks choler colour cholers colours clock cluck clocked clucked clocking clucking clocks clucks cob cub cobs cubs cod cud coddle cuddle coddled cuddled coddles cuddles coddling cuddling col cull cols culls collar colour collared coloured collaring colouring collars colours Colombia Columbia comma comer commas comers conning cunning cont cunt cop cup copped cupped copping cupping cops cups coppers cuppas Copt cupped corrie curry corries curries cot cut cots cuts cottar cutter cottars cutters cough cuff coughed cuffed coughing cuffing coughs cuffs crocks crux cropper crupper croppers cruppers crotch crutch crotches crutches dobbin dubbin dock duck docked ducked docking ducking docks ducks dog dug dogs dugs dog Doug doll dull dolled dulled dolling dulling dolls dulls dollar duller don done don dun donned dunned donning dunning dons duns donjon dungeon donjons dungeons dossed dost flocks flux florid flurried fog fug fogs fugs foggy fuggy foggier fuggier foggiest fuggiest fond fund fosse fuss fosses fusses fox fucks golf gulf golfs gulfs golly gully goner gunner goners gunners gosh gush gosling guzzling got gut hob hub hobs hubs hobby hubby hobbies hubbies hog hug hogged hugged hogging hugging hogs hugs Hon Hun honk hunk honks hunks horrid hurried horridly hurriedly hot hut hotted hutted jog jug jogged jugged jogging jugging jogs jugs joggle juggle joggled juggled joggles juggles joggling juggling jot jut jots juts jotted jutted jotting jutting knob nub knobs nubs knot nut knotted nutted knotty nutty knottier nuttier knottiest nuttiest loch luck lochs luxe lock luck locks luxe loft luffed log lug logged lugged logging lugging logs lugs loll lull lolled lulled lolling lulling lolls lulls long lung longs lungs lost lust mock muck mocked mucked mocking mucking mocks mucks Mod mud model muddle modelled muddled modelling muddling models muddles Mods muds moll mull molls mulls mosque musk moss muss mosses musses monster Munster nozzle nuzzle nozzles nuzzles op up opt upped otter utter otters utters oz us plonk plunk plonks plunks pock puck pocks pucks podgy pudgy podgier pudgier podgiest pudgiest pommel pommel pommels pommels pomp pump pond punned pop pup pops pups poppet puppet poppets puppets poppy puppy poppies puppies pot putt pots putts potted putted potting putting potter putter pottered puttered pottering puttering potters putters potty puttee potties puttees potty putty rhomb rum rob rub robbed rubbed robbing rubbing robs rubs robber rubber robbers rubbers robbery rubbery roc ruck rocs rucks rock ruck rocked rucked rocking rucking rocks rucks romp rump romps rumps Ron run Ronnie runny rot rut rots ruts rotted rutted rotting rutting scholar sculler scholars scullers scoff scuff scoffed scuffed scoffing scuffing scoffs scuffs Scot scut Scots scuts shock shuck shocked shucked shocking shucking shocks shucks shot shut shots shuts shone 'shun shone shun slog slug slogged slugged slogging slugging slogs slugs slosh slush slot slut slots sluts smog smug snob snub snobs snubs snog snug snogs snugs sob sub sobbed subbed sobbing subbing sobs subs soccer succour sock suck socked sucked socking sucking socks sucks sodden sudden sods suds soft soughed solid sullied song sung sop sup sopped supped sopping supping sops sups spotter sputter spotters sputters stock stuck stomp stump stomped stumped stomping stumping stomps stumps strong strung sorry Surrey toff tough toffee toughie toffees toughies toff tough toffs toughs tog tug togged tugged togging tugging togs tugs Tommy tummy tongs tongues top tup topped tupped topping tupping tops tups tot tut totted tutted totting tutting tots tuts wan one wan won wander wonder wandered wondered wandering wondering wanders wonders warrior worrier warriors worriers wrong rung wrongs rungs
John Higgins, Shaftesbury, January 2010