"My bag is not taken by them."
Translation:Tas saya tidak diambil mereka.
Is "Tas saya tidak diambil mereka" really correct? Shouldn't it be "... diambil oleh mereka"?
When is oleh needed?
Both are fine.
'oleh' can be omitted if the passive 'di-' verb is directly followed by the agent/actor.
'oleh' must be used if the passive verb is followed something else than the agent/actor.
agent/actor = the one performing the action of the verb ==> 'mereka'.
Here is another example: