fikir

/fikir/

Cases

SingularPluralWhen to use it
nominativefikirthe thoughtfikirlethe thoughtsthe plain dictionary form — the doer of the sentence
genitivefikirnithe thought'sfikirlenithe thoughts'the owner — whose it is
accusativefikirnithe thought (as the object)fikirlenithe thoughts (as the object)a specific, known object — whom or what
dativefikirgeto the thoughtfikirlegeto the thoughtsdirection or recipient — to where, to whom
locativefikirdeat / in the thoughtfikirledeat / in the thoughtswhere it is; also having — mende bar, "I have it"
ablativefikirdenfrom the thoughtfikirledenfrom the thoughtswhere 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
myfikirimmy thoughtfikirlerimmy thoughts
yourfikiringyour thoughtfikirleringyour thoughts
his / herfikirihis / her thoughtfikirlerihis / her thoughts
ourfikiribizour thoughtfikirleribizour thoughts
you all'sfikirigizyou all's thoughtfikirlerigizyou all's thoughts
theirfikirleritheir thoughtfikirleritheir thoughts

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