Sometimes the prepositional phrase in a sentence tells more about the action. In that case, we call it an adverbial prepositional phrase because it acts like an adverb, modifying the verb.
Look at this sentence: The boy walked down the stairs.
The prepositional phrase down the stairs tells more about how the boy walked. This prepositional phrase acts like an adverb, modifying the verb.
Here are more examples of prepositional phrases modifying the verb:
The cross country team ran around the track.
The phrase around the track tells more about how the team ran.
The truck drove through a tunnel.
The phrase through a tunnel tells more about how the truck drove.
On vacation, we slept in a tent.
The phrase in a tent tells more about how we slept.
An adverbial prepositional phrase modifies the action in a sentence.
▶It’s your turn. Find the prepositional phrase in this sentence that modifies the action. The man in the car looked out the window. Did you find the phrase that gives more information about how the man looked? Good for you.