This is the 199th most frequent Serbian word.
наша
"Наша" means "our" in English.
In this sentence, "наша" is a possessive pronoun in feminine singular form, used to indicate ownership of the noun "кућа" (house).
Наша кућа се налази у близини школе.
Our house is located near the school.
"Наша" here functions as a possessive pronoun of feminine singular form and agrees with the noun "одговорност" (responsibility).
Ово је наша одговорност.
This is our responsibility.
The word "наша" serves as a possessive adjective referring to "групу" (group), which is feminine singular.