What is the prepositional phrase in sentence tornado uprooted trees and roof of houses were blown away?

Here's why:

* Prepositional phrases consist of a preposition (like "of," "in," "on," etc.) followed by its object (a noun or pronoun).

* In this case, "of" is the preposition, and "houses" is the object.

The prepositional phrase modifies the noun "roof," telling us what kind of roof was blown away.