Questions & Answers about Detektiv je nazvao operatora.
Je is the 3rd person singular present form of biti (to be), and it is used as an auxiliary to form the past tense.
So:
- je nazvao = called / has called
In Croatian, the usual past tense is made with:
- the auxiliary biti
- plus a past participle
So Detektiv je nazvao operatora. is a normal past-tense sentence.
Nazvao is the masculine singular past participle form of the verb nazvati (to call).
It agrees with the subject:
- detektiv is masculine singular
- so the participle is nazvao
Compare:
- Detektiv je nazvao... = masculine singular
- Detektivka je nazvala... = feminine singular
- Dijete je nazvalo... = neuter singular
- Detektivi su nazvali... = masculine plural or mixed plural
So the ending -ao here matches a masculine singular subject.