seriya

/serija/

Cases

SingularPluralWhen to use it
nominativeseriyathe seriesseriyalathe seriesthe plain dictionary form — the doer of the sentence
genitiveseriyanıthe series'seriyalanıthe series'the owner — whose it is
accusativeseriyanıthe series (as the object)seriyalanıthe series (as the object)a specific, known object — whom or what
dativeseriyağato the seriesseriyalağato the seriesdirection or recipient — to where, to whom
locativeseriyadaat / in the seriesseriyaladaat / in the serieswhere it is; also having — mende bar, "I have it"
ablativeseriyadanfrom the seriesseriyaladanfrom the serieswhere 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
myseriyammy seriesseriyalarımmy series
yourseriyangyour seriesseriyalarıngyour series
his / herseriyasıhis / her seriesseriyalarıhis / her series
ourseriyabızour seriesseriyalarıbızour series
you all'sseriyağızyou all's seriesseriyalarığızyou all's series
theirseriyalarıtheir seriesseriyalarıtheir series

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