Some four letter words with a second letter U are:auraburncurbcuredulldumbeurofundguruhugejumpjunklumpluremuchmutenudeoustpullpurepushrulerumpruinruserushrustsuchsurftune
Some four letter words with second letter U and fourth letter O are:autoeurojudokudoouzo
Haul and laud are four letter words. The 2nd letter is a. The 3rd letter is u.
dyes
Some four-letter words with the second letter "o" include: book, food, foot, pool, look, loop, cool, and soon. These words all have the commonality of having the letter "o" as the second letter in their spelling.
Star, stat, stop, stir, and step are some four letter words with the second letter 't'
burnbunkbuntbuttbustbuckbullburpbumpcutecubecurtdumpdukedunkdulldustduckduskdunedungfundfullfunkfussfusegustgunkhushhunthuskhurthullhunghunkhumpjustjunklumplushlurelustlulllungmuttmustmuchmushmusemutemulenutsoustpullpushpumppunkpuntpurequitrustrungrushruntrulesulksunksuretune
Ayes, byes, cyst, eyed and gyms are four letter words. Additional four letter words include gyro, hymn, lynx, myth, type and typo.
Were and here are four letter words. Additional words include mere and fete (to honor with a celebration).
addseggsoddsAnnebeefbeenbeepbeerbeetbootbookboomboonbooscoolcootdeerdeepdeeddeemdoordoomfeedfeelfeetfoodfoolfootgoodgeedgoofgoongoopheedheelheedhoodhoofhoophootjeepjeerkeepkeelkeenleekleerloonloomlooplootmeetmoodmoonmoormootneednooknoonpeerpoofpeelpoolpeeppeerroofroomrootreedreelseedseemseenseerseessoonteentooltootwoolweedwoodwoofweep
unto, undo, updo
calf is one barf another