The /æ/ vowel is spelled <a> followed by two consonants or by one consonant in a monosyllable. The normal spelling of the /ɑ/ vowel is <ar> as in bark, but we also find <er> in clerk and <ear> in heart. There are also several spellings without <r> such as <al> in calm and halve, <au> in aunt, <as> in mast and glassy, as well as a number of irregular spellings in loan words such as lakh and khan.
Although all these pairs are minimal for speakers of RP, only 21 pairs are minimal for speakers of rhotic accents (those accents in which /r/ may occur before other consonants or silence), probably the majority of English speakers. I have marked the pairs with * where there is no <r> in the spelling, and the one case (the homograph pair tarry = wait v. tarry = covered in tar, marked **) in which both the number 4 and number 5 vowels are followed by <r>; these pairs would be either homophones or minimal pairs for all speakers.
This is a contrast bewteen a short and a long vowel. Nevertheless, many foreign learners, and especially those who use a 5-vowel system, will find this one of the most difficult RP contrasts. It is a known problem for French, Spanish, Greek, and Swahili speakers.
There is one taboo word pairing: fat/fart.Interesting pairs include:
matter martyr
vanish varnish
The mean density is 2.4%. The pairs make 98 semantic contrasts, giving a loading of 54%.
adder ardour adders ardours am arm ant aren't ante auntie * antes aunties * ants aunts * as R's at Art ax arcs babble barbel babbles barbels Babs barbs back bark backed barked backer barker backers barkers backing barking backs barks bad bard badge barge badges barges bally barley banns barns Basil Basel * Bass baas * bat Bart bats Barts batter barter battered bartered battering bartering batters barters cad card cads cards caff calf * cam calm * cams calms * can Calne * cans khans * cant can't * cap carp capped carped capping carping caps carps cat cart Chad Chard Chas chars chat chart chats charts chatted charted chatter charter chattered chartered chattering chartering chatters charters chatting charting clack clerk clacked clerked clacking clerking clacks clerks Dakar darker Dan darn fat fart fats farts fatted farted fatting farting gab garb gabble garble gabbled garbled gabbles garbles gabbling garbling gad guard gadded guarded gadding guarding gads guards gaggle gargle gaggles gargles Gallic garlic gannet garnet gannets garnets glacier glassier * hack hark hacked harked hacking harking hacks harks had hard hallow Harlow ham harm hammed harmed hamming harming hams harms hap harp happed harped happing harping happy harpy haps harps hash harsh hat hart hath hearth hatless heartless have halve * haves halves * having halving * jazz jars knack nark knacks narks lack lakh * lacks lakhs * lack lark lacked larked lacking larking lacks larks lad lard lads lards ladder larder ladders larders lags Largs land larned latch larch latches larches lax lakhs lax larks mac mark mad marred Madge Marge Mallow Marlow masc mask * mash marsh mashes marshes massed mast * match march matched marched matches marches matching marching matins martens Matt mart matter martyr mattered martyred mattering martyring matters martyrs Max marks outmatch outmarch outmatched outmarched outmatches outmarches outmatching outmarching pack park packed parked packing parking packs parks packers parkas pallid parleyed pallor parlour pally parley Pam palm * patch parch patched parched patches parches patching parching pat part pats parts patted parted patting parting patties parties Patty party quack quark quacks quarks Sam psalm * shack shark shacks sharks shad shard stack stark tans tarns tarry tarry ** tassel tarsal tassel tarsals tat tart tats tarts tatted tarted tatting tarting tatter tartar tatters tartars vanish varnish vanished varnished vanishes varnishes vanishing varnishing