What topic is the teacher most likely introducing when explaining that the subject is the doer of the action in sentences with an action verb?

• A. Noun phrases
• B. Sentence fragments
• C. Subject-verb agreement
• D. Active and passive voice

Answer: (D)

Active and passive voice is being introduced. When the subject is performing the action with an action verb, the sentence is in the active voice. The subject is the doer, as in “The student wrote the essay,” where the student is doing the writing. Seeing the subject as the one who acts helps explain why the sentence feels direct and who is responsible for the action.

In contrast, the passive voice shifts focus to the action or its recipient: “The essay was written by the student.” Here the subject isn’t doing the action; the emphasis moves away from the doer, and the doer can appear in a “by” phrase or be left out entirely. Understanding this distinction clarifies why writers choose one form over the other and how to identify who is doing the action.

Noun phrases aren’t about who performs actions; sentence fragments are incomplete thoughts; subject-verb agreement is about matching number between subject and verb, not about who does the action.