This is the 14295th most frequent Turkish word.
okulunun
"Okulunun" means "of your school" or "your school's" in English.
In this sentence, 'okulunun' signifies possession, indicating 'of the school'. It functions as a genitive case marker in Turkish to show a relation to 'okul' where the suffix '-unun' defines ownership or association.
Kardeşimin gittiği okulunun bahçesi çok büyük.
The garden of the school my sibling attends is very large.
Here, 'okulunun' shows possession and attribution of the event organization to the school, combining 'okul' (school) with personalization or association provided by the suffix '-unun'.
Ali okulunun düzenlediği spor etkinliğine katıldı.
Ali participated in the sports event organized by his school.
In this context, 'okulunun' again indicates a possessive relation, where 'okul' is the possessor subject of the action, and '-unun' makes the context specific to 'your school'.