The /ɔ/ vowel is usually spelled <or>, <our>, and <oar>, but we also see <al> in hall, <au>, <aw> and <ar> after <w> in warship. The /3/ vowel is spelled <er>, <ir>, <ur>, <ear>, and <or> after <w> in worship.
This is a contrast between two long vowels. They are fairly close together in the mouth but are distinguished by lip-rounding. They can sometimes be a source of confusion, but are not a problem for any particular group of learners.
Interesting pairs include:
accord ocurred
auburn urban
former firmer
hoarse hearse
Mormon merman
porpoise purpose
sorely surly
The density figure is fairly high at 7.62%. The set makes 120 semantic contrasts giving a loading of 51.5%.
accord occurred all earl assort assert assorted asserted assorting asserting assorts asserts auburn urban auk irk auks irks awe err awed erred awes errs awl earl awls earls awning earning awnings earnings balk burke balked burked balking burking balks burkes bauble burble baubles burbles bawd bird bawds birds board bird boards birds blackboard blackbird blackboards blackbirds boar burr boars burrs bore burr bores burrs bored bird Bourne Bern bourn burn bourns burns calk kirk calks kirks call curl called curled calling curling calls curls caller curler callers curlers caught curt cause curs caw cur caws curs cawed curd chord curd chords curds coarse curse cord curd cords curds conform confirm conformed confirmed conforming confirming conforms confirms consort concert consorted concerted consorting concerting consorts concerts Corby Kirkby core cur cork kirk corks kirks corse curse corses curses course curse coursed cursed coursing cursing courses curses court curt courtly curtly exhort exert exhorts exerts exhorted exerted exhorting exerting export expert exports experts fall furl falling furling falls furls faun fern fauns ferns for fir for fur forced first fore fir fore fur form firm formed firmed forming firming forms firms former firmer four fir fours firs four fur fours furs gaud gird gauds girds gall girl gall girls Gaul girl Gauls girls ghat girt hall hurl halls hurls haul hurl hauled hurled hauling hurling hauls hurls hawed heard haws hers hoar her hoard heard hoard herd hoards herds hoarded herded hoarding herding horde heard horde herd hordes herds hoarse hearse horse hearse horses hearses horn Herne inform infirm lawn learn lawns learns more myrrh Mormon merman mortal myrtle mortals myrtles Norse nurse ore err orgies urges pall pearl palled pearled palling pearling palls pearls pall purl Paul Pearl pause purrs paw per paw purr pawed purred pawky perky pawkily perkily porch perch porches perches pore per pore purr poring purring pored purred pores purrs pour per pour purr pouring purring poured purred pours purrs pork perk porpoise purpose porpoises purposes port pert portly pertly record recurred seaboard seabird seaboards seabirds short shirt shorting shirting shorts shirts soar sir soars sirs soared surd sorely surly spawn spurn spawned spurned spawning spurning spawns spurns spore spur spores spurs sport spirt sported spirted sporting spirting sports spirts stalling Stirling store stir stored stirred stores stirs storing stirring talk Turk talks Turks talkie Turkey talkies turkeys thawed third torn tern torsion tertian vortex vertex vortices vertices walk work walked worked walking working walks works walker worker walkers workers wall whirl walled whirled walling whirling walls whirls war were war whirr warred whirred warring whirring wars whirrs warred word ward whirred ward word warded worded warding wording wards words warm worm warmed wormed warming worming warms worms warship worship warships worships wart wert whore her whores hers yaw year yaws years yawn yearn yawned yearned yawning yearning yawns yearns yore year
Credit: John Higgins