oyun

/ojun/

Cases

SingularPluralWhen to use it
nominativeoyunthe gameoyunlathe gamesthe plain dictionary form — the doer of the sentence
genitiveoyunnuthe game'soyunlanıthe games'the owner — whose it is
accusativeoyunnuthe game (as the object)oyunlanıthe games (as the object)a specific, known object — whom or what
dativeoyungato the gameoyunlağato the gamesdirection or recipient — to where, to whom
locativeoyundaat / in the gameoyunladaat / in the gameswhere it is; also having — mende bar, "I have it"
ablativeoyundanfrom the gameoyunladanfrom the gameswhere it comes from; also "than" when comparing
When to use each case
nominative
the plain dictionary form — the doer of the sentence
genitive
the owner — whose it is
accusative
a specific, known object — whom or what
dative
direction or recipient — to where, to whom
locative
where it is; also having — mende bar, "I have it"
ablative
where it comes from; also "than" when comparing

The endings are the same ones the pronouns wear — that page explains when each case is used.

With an owner

One ownedSeveral owned
myoyunummy gameoyunlarımmy games
youroyunungyour gameoyunlarıngyour games
his / heroyunuhis / her gameoyunlarıhis / her games
ouroyunubuzour gameoyunlarıbızour games
you all'soyunuğuzyou all's gameoyunlarığızyou all's games
theiroyunlarıtheir gameoyunlarıtheir games

The overlap in the last rows is real, not a mistake: oyunları can mean "his / her games", "their game", or "their games" — context decides.