The /ɔ/ vowel is usually spelled <or>, <our>, and <oar>, but we also see <al> in talk, <au> in gauze, <aw> in awe and <ar> after <w> in war and water. The /əʊ/ diphthong is usually spelled <oCe>, <oa> or <ow> but we also see <ou> in mould and the letter name O.
Although this is a contrast between a long vowel and a diphthong, the starting positions are close togther in the mouth and there is great potential for confusion, with both sounds associated with sounds in the learners' first language which have the letter o in spelling. It is a recognised difficulty for speakers of French, German, Greek, Russian, Turkish, Swahili, and probably many others.
Interesting pairs include:
cantors cantos
explored explode
mortar motor
paltry poultry
The density figure is 6.18%. The set makes 142 semantic contrasts giving a loading of 49.5%.
aboard abode alder older auburn Oban auger ogre augers ogres aught oat auk oak auks oaks awe O awes O's awed ode awing owing awning owning bald bold balder bolder baldest boldest baldly boldly baldness boldness ball bole balls boles bawd bode bawds bodes boar beau boars beaux boar bow boars bows bore beau bores beaux bore bow bores bows board bode boarded boded boarding boding boards bodes bourn bone calk coke calked coked calking coking calks coax call coal calls coals called coaled calling coaling caller cola callers colas cantors cantos caught coat causes cosies cawed code chalk choke chalked choked chalking choking chalks chokes chalky chokey chaws chose clause close clauses closes caw Co chord code chords codes coursed coast cord code cords codes corded coded coding cording cork coke corks cokes corks coax corm comb corms combs corn Colne corn cone corned coned corns cones corning coning corny coney corpse copes Corby Kobe Corp cope court coat courted coated courting coating courts coats crore crow crores crows daunt don't daw doe daws does drawl droll drawn drone explored explode fall foal falling foaling falls foals faugh foe faun phone fauns phones fawn phone fawned phoned fawning phoning fawns phones flaw flow flawed flowed flaws flows for foe fore foe form foam formed foamed forming foaming forms foams four foe fours foes fork folk forks folks galled gold gaud goad gauds goads Gaul goal Gauls goals gauze goes ghat goat ghats goats gnaw know gnawed node gnawing knowing gnaws knows hall hole halls holes haul hole hauls holes hauled holed hauling holing hauled hold haulier holier haulm home haw ho hawed hoed hawing hoeing haws hoes hawks hoax hoard hoed horde hoed horn hone horned honed horns hones horning honing Horley holy jaw Joe laud load lauded loaded lauding loading lauds loads law low laws lows lawn loan lawns loans lord load lords loads lorded loaded lording loading malt moult malted moulted malting moulting malts moults Maud mode maul mole mauls moles maw mow maws mows more mow morn moan mourn moan mourned moaned mourning moaning mourns moans mauled mould mortar motor mortared motored mortaring motoring mortars motors norm gnome norms gnomes nought note noughts notes order odour orders odours overawed overrode oversaw oversew pall pole palled polled palling polling palls poles paltry poultry pause pose paused posed pauses poses pausing posing pawky poky pawn pone pawns pones porch poach porches poaches pork poke porker poker porkers pokers portable potable portion potion portions potions prawn prone punchball punchbowl punchballs punchbowls quart quote quarts quotes quarters quotas raw roe roared road roars Rose saw sew sawed sewed sawing sewing sawn sewn saws sews saw sow saws sows sawing sowing sawn sown scald scold scalded scolded scalding scolding scalds scolds scrawl scroll scrawls scrolls scrawling scrolling scrawled scrolled shawl shoal shawls shoals shored showed shore show shored showed shores shows shorn shown slaw sloe snore snow snored snowed snores snows sorely solely stalk stoke stalked stoked stalker stoker stalkers stokers stalking stoking stalks stokes stall stole stalls stoles store stow stored stowed stores stows strawed strode talk toque talks toques taught tote taut tote tor toe tors toes tor tow tors tows tore toe tore tow torn tone tawny Tony torpor toper torpors topers tort tote torts totes trawl troll trawled trolled trawling trolling trawls trolls vault volt vaults volts walk woke walled wold war woe wars woes ward woad York yoke
Credit: John Higgins