This is the 1st most frequent Slovenian word.
je
"Je" in Slovenian means "is."
In this usage, 'je' is part of the past tense construction, paired with the past participle (bilo) to indicate a completed action in a passive voice construction.
Potrdilo je bilo podpisano.
The certificate has been signed.
In this sentence, 'je' functions as a third-person singular present tense form of the verb 'to be' (biti) in Slovenian, equivalent to 'is' in English.
Janez je zdravnik.
Janez is a doctor.
Here, 'je' serves as the main verb in a question, inquiring about the current state related to time, continuing its role as the verb 'to be' (biti).