with any accompanying qualifiers: the old rusty tractor. A prepositional phrase combines a preposition (in, with, under, beside, after, of, by, etc.) with a noun or noun phrase: under the tractor or beside the old rusty tractor. Some prepositions can also function as subordinating conjunctions. After the race is a prepositional phrase, since it lacks a verb-form; after the race was run is a (subordinate, adverbial) clause—introduced by the “conjunction” after—because the addition of the verb form