The /ʃ/ sound is spelled with <sh> and <ch> in chaise and Boche. The /ʧ/ sound is spelled with <ch> or <tch>.
This is a contrast between a fricative and an affricate, both voiceless and in the same region of the mouth. It is a known problem for many learners, including speakers of French, Dutch, Scandinavian languages, Spanish, Greek and Thai.
Taboo word pairs include shat/chat and shit/chit.
Interesting pairs include:
The mean density value is 2.1%. The lists make 56 semantic distinctions, a loading of 43%.
bash batch bashes batches Boche botch bush butch cache catch caches catches caching catching cash catch cashes catches cashing catching chic cheek crush crutch crushes crutches dish ditch dished ditched dishes ditches dishing ditching fuchsia future fuchsias futures hash hatch hashed hatched hashes hatches hashing hatching hush hutch hushes hutches lash latch lashed latched lashes latches lashing latching leash leach leashes leaches leash leech leashes leeches marsh march marshes marches mash match mashed matched mashes matches mashing matching mush much nosh notch noshed notched noshes notches noshing notching push putsch pushes putsches racial Rachel rash ratch rashes ratches reddish Redditch shad Chad shaft chaffed shah char shahs chars shan't chant shard Chard share chair shared chaired shares chairs sharing chairing shat chat shatter chatter shattered chattered shattering chattering shatters chatters sheaf chief shear cheer sheared cheered shearing cheering shears cheers sheer cheer sheet cheat sheeting cheating sheets cheats sherry cherry sherries cherries shied chide shilling chilling shin chin shins chins shine chine shines chines shipboard chipboard ship chip shipped chipped shipping chipping ships chips shit chit shock chock shocked chocked shocking chocking shocks chocks shoe chew shoeing chewing shoes chews shoo chew shooed chewed shoos chews shooing chewing shop chop shopped chopped shopping chopping shops chops shopper chopper shoppers choppers shore chaw shored chawed shores chaws shore chore shores chores shows chose shuck chuck shucked chucked shucking chucking shucks chucks splosh splotch sploshes splotches swish switch swished switched swishes switches swishing switching wash watch washed watched washes watches washing watching washer watcher washers watchers wish which wish witch wishes witches wishing witching
Credit: John Higgins