bel

/ bel /

Cases

SingularPluralWhen to use it
nominative bel the waist belle the waists the plain dictionary form — the doer of the sentence
genitive belni the waist's belleni the waists' the owner — whose it is
accusative belni the waist (as the object) belleni the waists (as the object) a specific, known object — whom or what
dative belge to the waist bellege to the waists direction or recipient — to where, to whom
locative belde at / in the waist bellede at / in the waists where it is; also having — mende bar, "I have it"
ablative belden from the waist belleden from the waists 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
my belim my waist bellerim my waists
your beliŋ your waist belleriŋ your waists
his / her beli his / her waist belleri his / her waists
our belibiz our waist belleribiz our waists
you all's beligiz you all's waist bellerigiz you all's waists
their belleri their waist belleri their waists

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