A prepositional phrase is a group of words that begins with a preposition and contains as the object of the preposition a noun or pronoun. Preceding the noun or pronoun, there can also be an article (an, a, the) or adjectives.
(a) an adjective phrase is a prepositional phrase that is used as an adjective. That is, like an adjective, this phrase modifies a noun or pronoun and answers the questions What kind? or Which one?
EXAMPLE: The group of boy scouts visited the museum. This prepositional phrase modifies the noun group because it answers the question Which group/Which one?
*an adjective phrase may also modify the noun of another prepositional phrase, as, in for example,
The name of the hero in this myth is Thlihan. (hero is the object of the preposition of, but "in this myth" modifies hero --answering Which one?)
(b) an adverb phrase is a prepositional phrase that is used as an adverb. That is, like an adverb, this phrase modifies a verb, an adjective, or an adverb and can answer these questions: How? When? Where? Why? or To what extent? (that is, how long, how far, or how many)
EXAMPLES: Julie stared (1)at the new car (2)in amazement.
(1) answers the question Where? while (2) answers the question How?
These prepositional phrases modify the verb "stared."
Sometimes a prepositional phrase will begin a sentence, so it can come before the word that it modifies. So, using the questions suggested to find this word that the phrase modifies is very helpful.
EXAMPLE: In their rush, Mary and Joe forgot to lock the house. This prepositional phrase modifies the verb forgot, answering the question How?
HINT: Using the questions that prepositional phrases answer will assist you in deciding what word these phrases modify.