The document discusses prepositions and prepositional phrases. It provides examples of sentences with blank spaces to be filled in by the correct prepositional phrase. The answers are also given. It emphasizes that a prepositional phrase begins with a preposition and ends with a noun or pronoun, and gives the example of "into the dark cave" as a completed prepositional phrase. It stresses the importance of using prepositions and prepositional phrases accurately in writing.