What is defined as a simple sentence?

A simple sentence is defined as a single independent clause, which means it contains a subject and a predicate and expresses a complete thought. This structure allows it to stand alone as a complete sentence. For example, "The cat sleeps" is a simple sentence because it presents one clear idea with both a subject ('the cat') and a verb ('sleeps').

In contrast, the other options refer to more complex sentence structures. A sentence that includes multiple clauses, such as those with both independent and dependent clauses, does not fit the definition of a simple sentence. Similarly, a sentence with two or more independent clauses forms a compound sentence, while a sentence that combines independent and dependent clauses is classified as a complex sentence. Therefore, the defining characteristic of a simple sentence—being comprised of a single independent clause—makes the correct answer clear.