"Dia masinis kereta ini, bukan penumpang."

Translation: He is this train's engineer, not a passenger.

[Ria___]

I think it should also accept "He is the engineer of this train, not a passenger."

[Fred_Van]

The English should read "not a passenger".

[joeldipops]

Got told "You used the wrong word" for saying "She is the engineer" not "He"

I somehow thought allowing he/she was automated.

[AndyBirtwistle]

It is train driver or driver of the train not train engineer.

[DanRL69]

Masinis is a vehicle driver (see KBBI dictionary) but that is marked wrong by Duolingo