This is the 403rd most frequent Turkish word.
ailesi
"His/her family" or "the family."
Here, "ailesi" reflects 'his/her family', which implies association and ownership without explicitly mentioning the possessor in the sentence.
Ailesi, ona daima destek oldu.
His/her family has always supported him/her.
In this sentence, "ailesi" refers to 'Ahmet's family', indicating possession using a genitive structure in Turkish.
Ahmet'in ailesi tatilde güzel zaman geçiriyor.
Ahmet's family is having a great time on vacation.
In this case, "ailesi" means 'his/her family', linking the possessor ('my neighbor') to the group (the family involved).