içki

/itʃki/

Cases

SingularPluralWhen to use it
nominativeiçkithe drinkiçkilethe drinksthe plain dictionary form — the doer of the sentence
genitiveiçkinithe drink'siçkilenithe drinks'the owner — whose it is
accusativeiçkinithe drink (as the object)içkilenithe drinks (as the object)a specific, known object — whom or what
dativeiçkigeto the drinkiçkilegeto the drinksdirection or recipient — to where, to whom
locativeiçkideat / in the drinkiçkiledeat / in the drinkswhere it is; also having — mende bar, "I have it"
ablativeiçkidenfrom the drinkiçkiledenfrom the drinkswhere 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
myiçkimmy drinkiçkilerimmy drinks
youriçkingyour drinkiçkileringyour drinks
his / heriçkisihis / her drinkiçkilerihis / her drinks
ouriçkibizour drinkiçkileribizour drinks
you all'siçkigizyou all's drinkiçkilerigizyou all's drinks
theiriçkileritheir drinkiçkileritheir drinks

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