Here's why:
* Prepositional Phrases: These consist of a preposition (like "on", "in", "with", "to", "from", etc.) followed by a noun or pronoun (the object of the preposition).
* Adverbial Phrases: These modify verbs (or adjectives or adverbs), providing information about how, when, where, or to what extent an action is performed.
Example:
* The cat sat on the mat.
Here, "on the mat" is a prepositional phrase. It modifies the verb "sat" by telling us where the cat sat. Since it modifies the verb, it acts as an adverbial phrase.
Let me know if you'd like more examples!