penal

/penal/

Cases

SingularPluralWhen to use it
nominativepenalthe pencil casepenallathe pencil casesthe plain dictionary form — the doer of the sentence
genitivepenalnıthe pencil case'spenallanıthe pencil cases'the owner — whose it is
accusativepenalnıthe pencil case (as the object)penallanıthe pencil cases (as the object)a specific, known object — whom or what
dativepenalğato the pencil casepenallağato the pencil casesdirection or recipient — to where, to whom
locativepenaldaat / in the pencil casepenalladaat / in the pencil caseswhere it is; also having — mende bar, "I have it"
ablativepenaldanfrom the pencil casepenalladanfrom the pencil caseswhere 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
mypenalımmy pencil casepenallarımmy pencil cases
yourpenalıngyour pencil casepenallarıngyour pencil cases
his / herpenalıhis / her pencil casepenallarıhis / her pencil cases
ourpenalıbızour pencil casepenallarıbızour pencil cases
you all'spenalığızyou all's pencil casepenallarığızyou all's pencil cases
theirpenallarıtheir pencil casepenallarıtheir pencil cases

The overlap in the last rows is real, not a mistake: penalları can mean "his / her pencil cases", "their pencil case", or "their pencil cases" — context decides.