The indirect case is used when the noun is followed by a post position otherwise the - ,
direct case is used .

Examples:
Masculine nouns on a larka boy

Singular larka (direct) larke (indirect)

Plural larke(direct) larkon (indirect)
Feminine nouns on i larki girl - : =
Singular larki (direct) larki (indirect )
Plural larkiyan (direct)(larkiyon indirect )