Final answer:
Without prepositional phrases, a sentence can lose important contextual information, but it doesn't change the clause structure into independent or dependent clauses, nor does it make the sentence complex.
Step-by-step explanation:
If prepositional phrases are missing from a sentence, the clarity of meaning could be significantly reduced. Prepositional phrases can add vital contextual information that clarifies when, where, or how something happens. For example, without a prepositional phrase, the sentence 'Marco jumped' lacks detail; however, adding 'after swimming in the ocean, Marco jumped in the pool' provides a complete picture of Marco's actions. The absence of prepositional phrases would not necessarily change a sentence into an independent or dependent clause, nor would it make a sentence complex. Clauses are related to the presence of subjects and verbs, as well as conjunctions that link them, rather than prepositions, which function to give additional information about other elements of the sentence.