Which of the following best defines a predicate?

The correct answer accurately defines a predicate as the part of the sentence that tells what the subject does. In English grammar, the predicate typically contains the verb and provides information about the action or state of being related to the subject. For example, in the sentence "The dog barks," the predicate is "barks," as it explains what the dog (the subject) is doing. A clear understanding of the predicate is essential for constructing complete and meaningful sentences, as it complements the subject by providing necessary action or description.

The other options do not encapsulate the concept of a predicate effectively. Describing a subject refers to adjectives or adjectival phrases, connecting clauses pertains to conjunctions, and a phrase that introduces a subject relates more to the subject of the sentence itself rather than what the subject is doing. This specific focus on action or completion of thought highlights why "the part of the sentence that tells what the subject does" is the best definition of a predicate.