The spelling of /t/ is usually <t> or <tt>, but we also see <ght> in bought and <th> in Thai. The /ʃ/ sound is commonly <sh> but has has many other spellings including <ch> in cloche, <sch> in borsch and <sc> in fascist, plus several arising from assimilations such as <ti> in patient, <ci> in facial or <su> in censure. Notice how the homograph tear makes pairs with share and shear.
The contrast is between a plosive and a fricative, both voiceless and fairly close together in the mouth. It is not a problem for learners.
The only taboo word pair is tag/shag.
This contrast is exploited by the name of a chain of fashion stores: Top Shop. Other interesting pairs include:
bracket brackish
fattest fascist
mitten mission
rennet Rhenish
tilling shilling
vanities vanishes
The mean density value is 1.4%. The list makes 155 semantic distinctions, a loading of 56%.
at ash bat bash batting bashing bought borsch bracket brackish brat brash cat cache centre censure centred censured centres censures centring censuring clot cloche cot cosh crate crèche ditties dishes ditty dishy fatal facial fatten fashion fattened fashioned fattening fashioning fattens fashions fattest fascist fit fish fitting fishing fitter fisher fitters fishers flat flash fret fresh gaiter geisha gaiters geishas garnet garnish GATT gash gnat gnash goat gauche got gosh gut gush gutting gushing gutter gusher gutters gushers harshly Hartley hart harsh hat hash hut hush jot Josh knot nosh knotting noshing lat lash lied leash mart marsh mat mash matting mashing matter masher matters mashers met mesh mitten mission mittens missions mutt mush Nat gnash not nosh owlet owlish patent patient patently patiently patents patients patten passion pattens passions plait plash plaiting plashing polities polishes pot posh potter posher potties poshes punnet punish put push rat rash ratter rasher ratters rashers rennet Rhenish rut rush rutting rushing sat sash slat slash slot slosh slotting sloshing slut slush squat squash squatting squashing T she T's she's ta shah tabby shabby tack shack tacked shacked tacking shacking tacks shacks tackle shackle tackled shackled tackles shackles tackling shackling tag shag tagged shagged tagging shagging tags shags tail shale take shake taken shaken takes shakes taking shaking takings shakings taker shaker takers shakers take-up shake-up tall shawl tallow shallow tame shame tamed shamed tames shames taming shaming tammy shammy tammies shammies tank shank tanks shanks tape shape taped shaped tapes shapes taping shaping tar shah tars shahs tare share tares shares tarred shard tat shat tatter shatter tattered shattered tatters shatters taught short taut short tauter shorter tautest shortest tautly shortly tautness shortness tawse shores tea she teas she's teak chic teal she'll tear share tears shares tearing sharing tear shear tearing sharing tears shears tease she's Ted shed Teds sheds tee she tees she's teeth sheath teethed sheathed teethes sheathes teething sheathing tell shell telling shelling tells shells Terry sherry Thai shy Thais shies Thame shame threat thresh tide shied tie shy ties shies tying shying tied shied tilling shilling tin shin tine shine tines shines tingle shingle tingled shingled tingles shingles tingling shingling tiny shiny tinier shinier tiniest shiniest tip ship tipped shipped tipping shipping tips ships tire shire tires shires to shoe to shoo toad shewed toddy shoddy toe shw toeing shwing toes shows told shoaled toll shoal tolling shoaling tolls shoals tolled shoaled tone shown ton shun tonning shunning tons shuns too shoe too shoo took shook toots chutes top shop topped shopped topping shopping tops shops topper shopper toppers shoppers tor shore tore shore torn shorn tort short torts shorts tot tosh tot shot tots shots tour sure tourist surest tout shout touted shouted touting shouting touts shouts tow show tows shows towed showed towing showing tower shower towered showered towering showering towers showers tread shred treading shredding treads shreds trews shrews trill shrill trilled shrilled trilling shrilling trills shrills trove shrove true shrew trunk shrunk tuck shuck tucked shucked tucking shucking tucks shucks tun shun tuns shuns turbot sherbet Turk shirk Turks shirks tut shut tuts shuts tutting shutting two shoo two shoe twos shoes Tyne shine utter usher uttered ushered uttering ushering utters ushers vanities vanishes watt wash welt Welsh welter welsher welters welshers what wash whit wish
John Higgins, Shaftesbury, February 2010.