object of the preposition Every preposition must have an object. Together, they make up a prepositional phrase. You can find the object of a preposition by asking “what?”. I slept under the bridge that night. Under what? Under the bridge. In English, an OP is always objective case. Greek: In Greek, the meaning of the preposition changes based on the case of the OP (BBG 8.3). Hebrew: See more on this page or this video.