Passive Voice
Passive voice is a grammatical construction where the subject of a sentence receives the action rather than performing it — often associated with formal writing and AI-generated text.
Definition¶
Passive voice is a sentence construction where the grammatical subject is the recipient of the action described by the verb, rather than the doer. In passive constructions, the agent (who does the action) is either absent or introduced with "by."
Active: The editor reviewed the manuscript. Passive: The manuscript was reviewed by the editor. Passive (agent omitted): The manuscript was reviewed.
When Passive Voice Appears¶
Passive voice is common in: - Scientific and academic writing — "Samples were collected at 24-hour intervals" emphasises methodology over researcher - Legal and institutional writing — "It has been determined that..." avoids assigning responsibility - News writing — "Three people were arrested" when the arresting party is obvious or irrelevant - Diplomatic communication — "Mistakes were made" avoids direct blame
Passive Voice and AI-Generated Text¶
Language models produce passive voice at significantly higher rates than typical human writers in the same genre. This is because formal writing — which dominates LLM training data — uses passive voice extensively. The result is AI text that consistently uses passive constructions where active voice would be more direct and natural.
This is one of the clearest stylistic markers AI detectors and human readers notice. Converting passive constructions to active ones is a standard step in humanizing AI output.
When Passive Is Correct¶
Despite its reputation, passive voice is not a grammatical error — it's a stylistic choice. It's the right choice when: 1. The receiver of the action is more important than the doer 2. The doer is unknown or irrelevant 3. You want to maintain topic continuity across sentences 4. The context is deliberately formal or institutional
The problem with AI-generated text isn't that it uses passive voice — it's that it uses it indiscriminately, including in contexts where active voice is clearly more appropriate.