* Prepositional phrases start with a preposition (like "on", "in", "to", "with", "for", etc.) and are followed by a noun or pronoun (the object of the preposition).
* "Visit" is a verb, not a preposition.
Here are some examples of prepositional phrases:
* to the store (preposition: "to", object: "store")
* with my friends (preposition: "with", object: "friends")
* on the table (preposition: "on", object: "table")
"Visit friends" is a verb phrase, where "visit" is the verb and "friends" is the object of the verb.