Prepositional phrases are not used to brighten up communications, they are very important descriptive devices.
'Grapefruit(s)' is the object of the preposition, not the 'subject'.
The noun comes after, not in front of, the preposition-- that is why it is called a 'pre'-'position'.
I can't imagine 'advance to' being a compound preposition (slide 8).
Eliminate the definition of 'verb' in slide 4: your topic is 'prepositions'.
Otherwise, good job and good luck.