dear ms. sue what is a propositional phrase
A prepositional phrase is a group of words that begins with a preposition and ends with a noun or pronoun.
Examples:
to the store
by the lake
under the green couch
in my old jacket
with Joe and Jane
toward home
of roses
If you memorize the common prepositions, you won't have any problem finding prepositional phrases.
http://www.englishclub.com/grammar/prepositions-list.htm