This is the 36th most frequent Serbian word.
он
"He" (third-person singular masculine pronoun).
Here, "он" is used as a subjective pronoun to represent the male subject in the sentence.
Он чита књигу.
He is reading a book.
In this sentence, "он" is used redundantly for emphasis to clarify the subject as "he."
Показао сам му писмо, јер је он то желео.
I showed him the letter because he wanted it.
Here, "он" serves its standard role as a nominative pronoun indicating the male person being talked about.