niet

/niet/

Cases

SingularPluralWhen to use it
nominativenietthe intentionnietlethe intentionsthe plain dictionary form — the doer of the sentence
genitivenietnithe intention'snietlenithe intentions'the owner — whose it is
accusativenietnithe intention (as the object)nietlenithe intentions (as the object)a specific, known object — whom or what
dativenietgeto the intentionnietlegeto the intentionsdirection or recipient — to where, to whom
locativenietdeat / in the intentionnietledeat / in the intentionswhere it is; also having — mende bar, "I have it"
ablativenietdenfrom the intentionnietledenfrom the intentionswhere 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
mynietimmy intentionnietlerimmy intentions
yournietingyour intentionnietleringyour intentions
his / hernietihis / her intentionnietlerihis / her intentions
ournietibizour intentionnietleribizour intentions
you all'snietigizyou all's intentionnietlerigizyou all's intentions
theirnietleritheir intentionnietleritheir intentions

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