Passive Voice - please note
1) Direct object (lijdend voorwerp -> je stelt de vraag "wie/wat + ondw. + gezegde in actieve zin -> antwoord = lijdend voorwerp)
2) Indirect object (meewerkend voorwerp -> aan/voor wie + ond. + gezegde actieve zin -> antwoord = meewerkend voorwerp)
3) Prepositional object (voorzetsel voorwerp -> naam/zelfstandig nmw na voorzetsel)
Direct object, indirect object and prepositional object in the active voice can all become subjects in the passive voice
He gave Sue a bouquet of red roses
1) A bouquet of red roses was given to Sue by him
2) Sue was given a bouquet of red roses by him
They laughed at John;
3) John was laughed at by them (preposition at the end of the sentence, before the agent);