jek

/dʒek/

Cases

SingularPluralWhen to use it
nominativejekthe evil spiritjeklethe evil spiritsthe plain dictionary form — the doer of the sentence
genitivejeknithe evil spirit'sjeklenithe evil spirits'the owner — whose it is
accusativejeknithe evil spirit (as the object)jeklenithe evil spirits (as the object)a specific, known object — whom or what
dativejekgeto the evil spiritjeklegeto the evil spiritsdirection or recipient — to where, to whom
locativejekdeat / in the evil spiritjekledeat / in the evil spiritswhere it is; also having — mende bar, "I have it"
ablativejekdenfrom the evil spiritjekledenfrom the evil spiritswhere 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
myjegimmy evil spiritjeklerimmy evil spirits
yourjegingyour evil spiritjekleringyour evil spirits
his / herjegihis / her evil spiritjeklerihis / her evil spirits
ourjegibizour evil spiritjekleribizour evil spirits
you all'sjegigizyou all's evil spiritjeklerigizyou all's evil spirits
theirjekleritheir evil spiritjekleritheir evil spirits

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