Read this sentence.

The protesters were concerned about traffic congestion.

Revise the sentence using prepositional phrases to make it more descriptive.

The protesters under the overpass were concerned about traffic congestion in the inclement weather during rush hour on 495 South.

Prepositional phrases can easily add description. They begin with a preposition that tells where one noun is in relation to another. They are words such as in, on, over, above, before, after, through, during, through, about, behind, with. The prepositional phrase ends in a noun or pronoun. For example, the prepositional phrase "about traffic congestion" begins with the preposition "about" and ends with the noun "congestion".