ertden

/ertden/

Cases

SingularPluralWhen to use it
nominativeertdenthe morningertdenlethe morningsthe plain dictionary form — the doer of the sentence
genitiveertdennithe morning'sertdenlenithe mornings'the owner — whose it is
accusativeertdennithe morning (as the object)ertdenlenithe mornings (as the object)a specific, known object — whom or what
dativeertdengeto the morningertdenlegeto the morningsdirection or recipient — to where, to whom
locativeertdendeat / in the morningertdenledeat / in the morningswhere it is; also having — mende bar, "I have it"
ablativeertdendenfrom the morningertdenledenfrom the morningswhere 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
myertdenimmy morningertdenlerimmy mornings
yourertdeningyour morningertdenleringyour mornings
his / herertdenihis / her morningertdenlerihis / her mornings
ourertdenibizour morningertdenleribizour mornings
you all'sertdenigizyou all's morningertdenlerigizyou all's mornings
theirertdenleritheir morningertdenleritheir mornings

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