In this lesson you will learn about prepositional phrases functioning as adverbs. Depending on the sentence a prepositional phrase can function as an adverbial adjunct. When a prepositional phrase functions as an adverbial adjunct where the adverb modifies the verb. For example in the sentence "David was reading in the garden." In this example the prepositional phrase "in the garden" provides information about where the subject is performing the action of the sentence, in this example the action is reading.