Questions & Answers about On je blizanac.
- On = he
- je = is
- blizanac = twin (masculine singular)
So the sentence literally matches English quite closely: He is a twin.
Je is the 3rd person singular present tense of the verb biti (to be).
So:
- ja sam = I am
- ti si = you are
- on/ona/ono je = he/she/it is
In On je blizanac., je links the subject on with the noun blizanac, just like is in English.