Special Agent Entrance Practice Exam

In passive voice sentences, the key characteristic is that the action is performed on the subject rather than the subject performing the action. This structural change shifts the focus from who is doing the action to who is receiving the action. For instance, in the passive sentence "The book was read by Mary," the book (the subject) is receiving the action of being read, indicating that the emphasis is on the book rather than on Mary, who is performing the action.

This contrasts with active voice, where the subject clearly performs the action (e.g., "Mary read the book"). In the context of the other options, while the omission of the subject can occur in passive constructions, it is not a defining feature that characterizes passivity; rather, it can happen for various reasons in both active and passive sentences. Additionally, passive voice sentences always contain a verb, so the lack of a verb is also not applicable.