fon

/fon/

Cases

SingularPluralWhen to use it
nominativefonthe backgroundfonlathe backgroundsthe plain dictionary form — the doer of the sentence
genitivefonnuthe background'sfonlanıthe backgrounds'the owner — whose it is
accusativefonnuthe background (as the object)fonlanıthe backgrounds (as the object)a specific, known object — whom or what
dativefongato the backgroundfonlağato the backgroundsdirection or recipient — to where, to whom
locativefondaat / in the backgroundfonladaat / in the backgroundswhere it is; also having — mende bar, "I have it"
ablativefondanfrom the backgroundfonladanfrom the backgroundswhere 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
myfonummy backgroundfonlarımmy backgrounds
yourfonungyour backgroundfonlarıngyour backgrounds
his / herfonuhis / her backgroundfonlarıhis / her backgrounds
ourfonubuzour backgroundfonlarıbızour backgrounds
you all'sfonuğuzyou all's backgroundfonlarığızyou all's backgrounds
theirfonlarıtheir backgroundfonlarıtheir backgrounds

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