In passive voice sentences, what is the primary characteristic?

In passive voice sentences, the primary characteristic is that the subject does not actively perform the action. Instead, the action is being performed on the subject by someone or something else.

For example, in a passive construction like "The book was read by the teacher," the subject "the book" is not the doer of the action (reading); rather, it is receiving the action from the teacher. This contrasts with active voice, where the subject performs the action directly, such as in "The teacher read the book."

Other options do not accurately describe the nature of passive voice. A sentence containing multiple subjects does not inherently indicate a passive construction. Similarly, beginning a sentence with a question word or stating that the subject performs the action of the verb are characteristics associated with different sentence structures.