üs

/ys/

Cases

SingularPluralWhen to use it
nominativeüsthe topüslethe topsthe plain dictionary form — the doer of the sentence
genitiveüsnüthe top'süslenithe tops'the owner — whose it is
accusativeüsnüthe top (as the object)üslenithe tops (as the object)a specific, known object — whom or what
dativeüsgeto the topüslegeto the topsdirection or recipient — to where, to whom
locativeüsdeat / in the topüsledeat / in the topswhere it is; also having — mende bar, "I have it"
ablativeüsdenfrom the topüsledenfrom the topswhere 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
myüsümmy topüslerimmy tops
yourüsüngyour topüsleringyour tops
his / herüsühis / her topüslerihis / her tops
ourüsübüzour topüsleribizour tops
you all'süsügüzyou all's topüslerigizyou all's tops
theirüsleritheir topüsleritheir tops

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