oh my gosh there are so many words that start with un, more words than i think any of us have the time to type out. here, how about this, about 85% of the words you say, only one that are adjectives(describing words) and verbs(things that you do) can also start with un, which means that you are not that thing or you are undoing what you did.
Some words associated with 'start' are:buttonfalseheadjumpkeylinestoptimewithup
Words with prefix un include unhappy, unsanitary, unwell, undone, uncompromising, unbelievable, unsettling, unassuming, unimaginative, unsaid... Many adjectives can be formed by adding the prefix un- to another adjective (that does not have a prefix already).
audioauditoryauditorium
Nabob, nudnik, and niggling are funny words that start with the letter n.
Missallaeneous
Some words that use the prefix 'un' are:unableunbelievableunconsciousundeniableunendingunfurledungainlyunholyunimaginableunjustunknownunlovedunmeritedunnoticedunownedunprovenunquietunrestunsinkableuntidyunusedunvariedunwantedunexplained (OK, so I cheated a little)unyieldingunzip
UndesirableUntamedunansweredunexplainedUnreliableUneasyUnderstandUndermineUnderlineUnderwearUndoUntoUntilUnitUniteUnionUnlessUnderage
unpleasant
Some words that start with a short U sound are up, us, under, and umpire.
un uniforme a uniform
UnhappyUnhealthyUncooperativeUnusualUnnecessaryUnderUndoUncleUnthoughtfulUnpreparedUndecidedUnapproched
un OR una
un africain, un ardéchois.
un youyou (masc.) (kind of light boat)
unfit & unable
unbelievable, unusual, unnatural, uneven, unwarranted
Some words that start with 'pat' are:patchpatepatentpaternalpaternitypathpathologypathospatiencepatientpatinapatiopatootiepatriarchpatricidepatriotpatrolpatronpatroonpatsypatterpatternpatty