The /æ/ vowel is spelled <a> followed by two consonants or by one consonant in a monosyllable. There are many different spellings of the /u/ vowel represented here, including <oo>, <o> in >who, <ew> in brewed, <uCe> in flute, <ou> in soup and <ui> in bruit.
One of the sounds is short and the other long and they are well separated in the mouth, and so should not cause problems for learners.
One pair involving a mildly taboo term is Bab's/boobs. This will raise a smile particularly through the association with Barbara Windsor and a well-known scene in the film Carry On Camping in which she loses her brassière. Another more dangerous pair is can/coon, since the word coon, originally short for raccoon, is now chiefly used as an offensive term for black man.
Interesting pairs include:
paddle poodle
plateau Pluto
straddle strudel
The mean density is 2.2%. The set makes 85 semantic contrasts giving a loading of 49%.
addles oodles as ooze Bab's boobs bad booed baggy boogie bast boost bat boot bats boots batted booted batting booting battle Bootle batty booty brad brewed brads broods brat bruit brats bruits brat brute brats brutes cad cooed can coon cans coons Cannes coon cap coop capped cooped capping cooping caps coops Capt cooped cat coot cats coots Chad chewed Chas chews clad clewed crap croup craps croups dam doom dams dooms damn doom dammed doomed damming dooming damns dooms dash douche dashes douches fad food fads foods flak fluke flat flute flats flutes flattest flutist flax flukes gaff goof gaffs goofs gaffe goof gaffes goofs gal ghoul gals ghouls glad glued gram groom grams grooms had who'd Hal who'll ham whom hap hoop happed hooped happing hooping haps hoops has who's hatter hooter hatters hooters haves hooves Jan June jazz Jews lack Luke lacquer lucre lam loom lamb loom lambed loomed lambing looming lambs looms lap loop lapped looped lapping looping laps loops lass loose lasses looses lassie Lucy lat loot latter looter lazar loser lazars losers mad mood Maddy moody man moon manned mooned manning mooning mans moons mass moose masses mooses match mooch matched mooched matches mooches matching mooching mat moot matted mooted matting mooting mats moots paddle poodle paddles poodles pal pool palled pooled palling pooling pals pools pap poop plateau Pluto plateaus Plutos rabble rouble rabbles roubles ram rheum rammed roomed ramming rooming rams rooms rat root rats roots ratted rooted ratting rooting rattle rootle rattled rootled rattles rootles rattling rootling sap soup sapped souped sapping souping sapper super sappers supers saps soups scanner schooner scanners schooners scat scoot scatter scooter scatters scooters shad shooed shatter shooter shatters shooters slap sloop slaps sloops snack snook snacks snooks snap snoop snapped snooped snapping snooping snaps snoops span spoon spanned spooned spanning spooning spans spoons straddle strudel straddles strudels tat toot tatted tooted tatting tooting tattle tootle tattled tootled tattles tootles tattling tootling trad trued trap troop trapped trooped trapper trooper trappers troopers trapping trooping traps troops trap troupe traps troupes