Which sentence is in the passive voice?

• A. The paragraph was written by Bob.
• B. Bob wrote the paragraph.
• C. The paragraph writes by Bob.
• D. Bob is writing the paragraph.

Answer: (A)

Passive voice happens when the subject receives the action, not performs it. The telltale pattern is a form of to be plus a past participle, often with by to show who did the action. In the sentence The paragraph was written by Bob, The paragraph is the one that receives the action of writing, and was written is the form of to be plus the past participle of write. The by Bob part tells who did the action. So this sentence clearly shows passive voice.

The other options don’t fit this pattern. Bob wrote the paragraph is active voice: Bob is the doer and the subject of the sentence. The paragraph writes by Bob isn’t a standard English construction for passive voice; if we tried to use passive here, it would be The paragraph is written by Bob. Bob is writing the paragraph is also active, using present progressive with Bob as the doer.