Here's why:
* Predicate: The predicate is the part of a sentence that tells us something about the subject.
* Subject: The subject is the person, place, or thing the sentence is about. In this case, the subject is "ball".
* Verb: The verb is the action word or state of being in a sentence. In this sentence, the verb is "flew" which describes the action of the ball.
So, the sentence "Over fence flew ball" tells us that the ball flew over the fence.