tengiz

/teŋiz/

Cases

SingularPluralWhen to use it
nominativetengizthe seatengizlethe seasthe plain dictionary form — the doer of the sentence
genitivetengiznithe sea'stengizlenithe seas'the owner — whose it is
accusativetengiznithe sea (as the object)tengizlenithe seas (as the object)a specific, known object — whom or what
dativetengizgeto the seatengizlegeto the seasdirection or recipient — to where, to whom
locativetengizdeat / in the seatengizledeat / in the seaswhere it is; also having — mende bar, "I have it"
ablativetengizdenfrom the seatengizledenfrom the seaswhere 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
mytengizimmy seatengizlerimmy seas
yourtengizingyour seatengizleringyour seas
his / hertengizihis / her seatengizlerihis / her seas
ourtengizibizour seatengizleribizour seas
you all'stengizigizyou all's seatengizlerigizyou all's seas
theirtengizleritheir seatengizleritheir seas

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