1. Ask "What kind?" or "Which one?"
* Adjectival: If the prepositional phrase modifies a noun or pronoun by telling "what kind" or "which one," it's adjectival.
* Example: "The book on the table is mine." (The phrase "on the table" describes which book.)
* Adverbial: If the prepositional phrase modifies a verb, adjective, or another adverb by answering questions like "where," "when," "why," "how," or "to what extent," it's adverbial.
* Example: "I walked to the store." (The phrase "to the store" tells where the speaker walked.)
2. Look at the function of the prepositional phrase:
* Adjectival: It acts like an adjective, modifying a noun or pronoun.
* Example: "The woman with the red hat is my aunt." (The phrase modifies the noun "woman.")
* Adverbial: It acts like an adverb, modifying a verb, adjective, or another adverb.
* Example: "I read the book in the afternoon." (The phrase modifies the verb "read.")
Here's a table summarizing the key differences:
| Feature | Adjectival Prepositional Phrase | Adverbial Prepositional Phrase |
|-----------------|-----------------------------------|---------------------------------|
| Function | Modifies a noun or pronoun | Modifies a verb, adjective, or adverb |
| Answer | "What kind?" or "Which one?" | "Where," "When," "Why," "How," "To what extent?" |
Remember:
* Some prepositional phrases can be ambiguous and function as both adjectival and adverbial.
* Context is crucial in determining the function of a prepositional phrase.