Prepositional phrases begin with and end with:
Nouns...prepositions
Verbs...adverbs/pronouns
Pronouns...prepositions
Prepositions...nouns/pronouns
Adverbs/adjectives
Nouns...prepositions
Verbs...adverbs/pronouns
Pronouns...prepositions
Prepositions...nouns/pronouns
Adverbs/adjectives