This is the 72nd most frequent Serbian word.
свој
"Свој" means "one's own" in English.
Possessive reflexive form referring to the subject's own item (umbrella).
Он је изгубио свој кишобран.
He lost his umbrella.
Possessive reflexive form referring to the subject's own items (books).
Марија је понела своје књиге.
Maria took her books.
Generic possessive reflexive form referring to the subject's responsibilities.