WIKI
Leaving out the Italian (rigatoni, vermicelli, etc.), and other foreign words (tabi, pachisi, swami), and names/proper nouns (Bambi, Hopi), some of the more common include:
bikini
safari
fungi(there are many -us words that pluralize to -i, e.g. cacti, syllabi, stimuli, etc.)
quasi
wasabi
alibi
rabbi
graffiti
yeti
confetti
origami
tsunami
chili
deli
lei
ennui
taxi
When you skip foreign words, proper nouns, and plural forms, the list is pretty limited, indeed.
Some four letter words that end with "o" are:zerohaloherohobointojudokiloalsoaltoautoechomemoontopolosilosolotacotarotrioundoveto
Some four letter words that end in H are:bathwashwishbashhashhushmushpithmythhathpushpath
Some four letter words ending with T are:baitbeetbeltbentblotboatbootbuntcantcartcastchatclotcoltcultcurtdartdentdirtdoltdusteastfactfastfeetfeltfestfistfootfortfretgaitgiltglutgnathaltheathefthilthoothosthuntjestjiltjustkeptkiltknitknotlastlentlintlistlootlostlustMaltmartmastmeatmeetmintmistmoltmootmostmustneatnestomitoustpantpartpastpeatpentpestpintpoetportpuntquitraftrantrentriftrootruntrustSaltseatsentsiftsiltskitsnitsootsortspitspotsuetswattartteattenttestthattinttoottorttrotunitvastventvestvoltwaitwantwartwattweftweltwentweptwestwhetwiltyurt
Some four letter words that end in 'is' are:axisibisiristhis
dazedozefazegazehazelazemazerazesizetaze
spaz
Some four letter words ending in L are:ballbellbillboilbullcallcellcoilcoolcurlearlfailfallfeelfellfillfoilfoolfoulfowlfullgallgoalgillgullhallhailheelhellhillhulljelljailjowlkeelkilllolllullmallmailmealmillmoilmullnailnullpailpallpeelpillpollpoolpurlrailreelrollsailsealsellsillsoiltailtalltealtelltoiltooltollveilwailwallwealwellwillyellzeal
Some four letter words starting with S and ending with F are:selfserfsurf
zapp
help, kelp, yelp
Some four letter words beginning with P and ending with S:PadsPalsPansPapsParsPassPatsPawsPaysPeasPecsPegsPensPepsPetsPewsPicsPiesPigsPinsPipsPitsPlusPodsPolsPomsPopsPotsProsPubsPudsPugsPunsPupsPuts
Some four letter words starting with A are:ableacreafarajaralsoaltoareaAsiaautoaxle