What constitutes a complete sentence?

A complete sentence is defined as a grammatical unit that includes a subject, a verb, and expresses a complete thought. The presence of a subject is essential as it indicates who or what the sentence is about, while the verb conveys the action or state of being. Additionally, expressing a complete thought ensures that the sentence can stand alone and makes complete sense to the reader.

For example, the sentence "The cat sleeps" includes a subject ("The cat") and a verb ("sleeps"), and it conveys a complete idea without leaving the reader in suspense or requiring further information to understand the meaning. This is why the correct answer encompasses all three elements: a subject, a verb, and a complete thought.

Other options do not fulfill the criteria for a complete sentence. A combination of a subject and an adjective, or a subject and an adverb does not include a verb, and therefore cannot form a complete thought. Lastly, a statement that is merely a complete thought without adhering to grammatical structure lacks the necessary components that define a complete sentence in standard English.