I'm excited about hearing your brother on the radio this evening! What is the prepositional phrase in this sentence l?

"On the radio".

Prepositional phrases consist of a preposition, article, and noun, pronoun, or a verb acting as a noun.

"On" is our preposition, "the" is our article, and "radio" is our noun. Remember a prepositional phrase always starts with the preposition and ends with a noun or pronoun. If you remember this you will be able to identify the prepositional phrases in no time.