"The job of a teacher is teaching his students."

Translation: Tugas seorang guru adalah mengajar siswa-siswanya.

[VincentQuerta]

Why is "Tugas guru mengerjar siswa-siswanya" not accepted? Both "seorang" and "Adalah" aren't necessary.

[Speedy12846]

Why do you have the siswa?You only need the siswanya.

[dont_tread_on_me]

Because it's plural.