Identifying Active vs. Passive Voice

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Historical Context & Motivation

Every sentence tells a story about someone doing something. But languages didn't always have neat ways to show who did it versus what happened. The idea of grammatical voice (the way a sentence highlights the doer or the receiver of an action) has been studied for thousands of years. Understanding its history helps you see why voice is such a powerful tool in your own writing.

~500 BCE

Ancient Greek Grammarians

Greek scholars like Dionysius Thrax first described verb forms as active (energeia, meaning "activity") and passive (pathos, meaning "experience"). They noticed that verbs could flip the spotlight from the doer to the receiver.

~100 CE

Latin Grammar Codified

Roman grammarians adopted the active/passive distinction and built it into Latin verb endings. A Latin verb like amat ("loves") could become amatur ("is loved") just by changing its ending.

1700s

English Grammar Takes Shape

English grammarians like Robert Lowth and Lindley Murray wrote formal grammar books that taught voice as a core concept. Because English lost most of its verb endings, it uses helping verbs ("is," "was," "were") plus the past participle to form the passive.

1900s–Today

Style Guides & Modern Writing

Books like Strunk and White's The Elements of Style urged writers to prefer active voice for clarity. Today, teachers and editors still debate when passive voice is useful, especially in science writing and journalism.

The central question is simple but powerful: in any sentence, who is doing the action, and how does the sentence's structure reveal that? Once you can answer that question, you can identify voice — and you can choose the best voice for your own writing.

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Core Principles & Definitions

Before you can spot active and passive voice, you need to understand three key players in every sentence: the agent (the one performing the action), the action (the verb), and the receiver (the one the action happens to). Voice is all about which of these players gets the spotlight as the grammatical subject of the sentence.

Active Voice

The agent (doer) is the subject of the sentence and comes before the verb. Example: "The dog chased the cat." The dog does the chasing.

Passive Voice

The receiver becomes the subject, and the verb uses a form of "to be" + past participle. Example: "The cat was chased by the dog." The cat receives the action.

The Agent

The agent is whoever or whatever performs the action. In passive sentences the agent may appear in a "by" phrase ("by the dog") or may be left out entirely ("The cat was chased"). Identifying the agent is the key to understanding voice.

The Passive Formula

Passive voice always follows a pattern: form of "to be" + past participle. Look for helping verbs like is, am, are, was, were, been, or being paired with a past participle (often ending in -ed, -en, or -t).

✦ KEY TAKEAWAY

Think of a sentence like a movie scene. In active voice, the camera is pointed at the person doing the action — "The chef cooked the meal." In passive voice, the camera is pointed at the thing receiving the action — "The meal was cooked by the chef." The scene is the same, but the focus shifts. That's voice.

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Visual Explanation

The diagram below shows how the same action — a chef cooking a meal — looks in both active and passive voice. Notice how the sentence parts rearrange themselves, and how the passive version introduces a form of "to be" as a helping verb.

In the active row, the agent (the chef) sits in the subject position. In the passive row, the receiver (the meal) moves to the subject position, the verb gains a form of "to be," and the agent shifts to a "by" phrase.

Look at how the boxes swap positions. In active voice, the flow moves naturally from agent → verb → receiver. In passive voice, the receiver jumps to the front, the verb adds a helping verb, and the agent can appear at the end in a "by" phrase — or it can disappear entirely.

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How Passive Voice Is Formed

English forms the passive voice with a specific pattern. Once you know this formula, you can spot passive voice in any tense.

PASSIVE VOICE FORMULA

Subject (receiver) + form of "to be" + past participle + (by + agent)

Subject = the receiver of the action (now in the subject spot). Form of "to be" = is, am, are, was, were, been, being. Past participle = the verb form often ending in -ed, -en, or -t (e.g., cooked, eaten, built). By + agent = optional phrase that names the doer.

Passive Voice Across Different Tenses

The form of "to be" changes with the tense, but the past participle stays the same.

Tense	Active Example	Passive Example	"Be" Form Used
Simple Present	She writes the report.	The report is written by her.	is
Simple Past	He painted the mural.	The mural was painted by him.	was
Present Progressive	They are building a bridge.	A bridge is being built by them.	is being
Present Perfect	She has broken the record.	The record has been broken by her.	has been
Future (will)	The team will announce the winner.	The winner will be announced by the team.	will be

⚠️ Watch Out!

Not every sentence with "was" or "is" is passive. The sentence "She was happy" uses "was" as a linking verb, not a helping verb. For passive voice, you need "to be" plus a past participle. If there's no past participle, it's not passive.

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Identifying the Agent

One of the trickiest parts of passive voice is finding the agent — the person or thing that actually performs the action. In active voice, the agent is always the subject, so it's easy to find. In passive voice, the agent might appear in a "by" phrase, or it might be missing altogether. When the agent is missing, we call it an agentless passive (also called a "truncated passive" or "short passive").

Start by checking for the "be" + past participle pattern. If you find it, the sentence is passive. Then check for a "by" phrase to see if the agent is stated or missing.

Three Types of Agent Situations

The agent can appear as a subject, in a "by" phrase, or not at all.

Situation	Example	Agent
Active voice	Maya designed the poster.	Maya (subject)
Passive with agent	The poster was designed by Maya.	Maya ("by" phrase)
Agentless passive	The poster was designed last week.	Unknown / not stated

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Worked Example

Let's walk through a full analysis of two sentences to practice identifying voice and agent step by step.

Analyzing: "The novel was written by Toni Morrison in 1987."

Step 1 — Find the Main VerbLook at the verb phrase. We see "was written." The word "was" is a form of "to be," and "written" is the past participle of "write."

Verb phrase: was written (form of "be" + past participle)

Step 2 — Apply the Passive TestDoes the verb follow the formula "form of 'to be' + past participle"? Yes — "was" (past tense of "be") + "written" (past participle). This tells us the sentence is in passive voice.

Voice: Passive

Step 3 — Identify the SubjectThe grammatical subject is "the novel." In passive voice, the subject is the receiver of the action. The novel didn't do the writing — it received the writing.

Subject (receiver): the novel

Step 4 — Find the AgentLook for a "by" phrase. We see "by Toni Morrison." This tells us who performed the action of writing.

Agent: Toni Morrison (stated in the "by" phrase)

Step 5 — Rewrite in Active Voice (Check)To confirm, flip the sentence to active voice by making the agent the subject: "Toni Morrison wrote the novel in 1987." This confirms that Toni Morrison is the agent (doer) and the novel is the receiver.

Active rewrite: "Toni Morrison wrote the novel in 1987."

Analyzing: "Three windows were shattered during the storm."

Step 1 — Find the Main VerbThe verb phrase is "were shattered." The word "were" is a form of "to be," and "shattered" is the past participle of "shatter."

Verb phrase: were shattered

Step 2 — Apply the Passive Test"Were" (form of "be") + "shattered" (past participle) matches the passive formula.

Voice: Passive

Step 3 — Find the AgentIs there a "by" phrase? No. The phrase "during the storm" tells us when it happened, not who or what did the shattering. This is an agentless passive — the doer is not stated.

Agent: Not stated (agentless passive)

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When Active and Passive Voice Work Best

You may have heard that "active voice is always better," but that's an oversimplification. Both voices have strengths, and good writers choose strategically. Here's a comparison to help you decide.

Neither voice is inherently "wrong" — it depends on what you want to emphasize.

Feature	Active Voice	Passive Voice
Clarity	Usually clearer — the reader immediately knows who is doing what.	Can be vague if the agent is missing, but useful when the receiver matters more.
Sentence length	Tends to be shorter and more direct.	Often adds extra words ("was," "by"), making sentences longer.
Best for	Narratives, persuasive essays, action-oriented writing.	Science reports, news headlines, when the agent is unknown or unimportant.
Emphasis	Emphasizes who or what performs the action.	Emphasizes the action itself or the thing receiving it.
Example use	"Scientists discovered a new species."	"A new species was discovered." (focuses on the discovery, not the scientists)

✦ KEY TAKEAWAY

Think of voice like choosing a camera angle in a video game. Active voice is like a first-person view from the character doing the action — you see what they do. Passive voice is like switching to a camera focused on the object being affected. Neither angle is wrong — great directors (and great writers!) switch between them for effect.

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Connections to Advanced Grammar

Understanding voice opens the door to more advanced grammar concepts. As you move into higher-level writing and analysis, you'll encounter related ideas that build on what you've learned here.

These advanced topics all grow from the active/passive foundation.

Concept You Know Now	Advanced Connection	Why It Matters
Active vs. passive voice	Middle voice — the subject acts on itself (e.g., "The door opened").	Some sentences blur the line between active and passive.
"Be" + past participle	Get-passives — "She got promoted" instead of "She was promoted."	English has more than one way to form the passive.
Identifying the agent	Thematic roles — linguists label sentence roles as Agent, Patient, Theme, Experiencer, etc.	Voice is part of a larger system for understanding who does what in language.
Choosing voice for effect	Rhetorical analysis — examining how authors use voice strategically in speeches, essays, and literature.	Voice choice reveals an author's purpose and perspective.

In future courses, you'll analyze how writers and speakers choose voice to shape meaning, dodge responsibility, or highlight certain information. Political speeches, scientific articles, and legal documents all use voice strategically. The skill you're building right now — recognizing voice and finding the agent — is the foundation for that deeper analysis.

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Practice Problems

Try these five problems on your own. For each, identify whether the sentence is in active or passive voice, and name the agent if it is stated. Then check your answer.

PROBLEM 1 — CONCEPTUAL

Is the following sentence in active or passive voice? "The teacher explained the lesson."

PROBLEM 2 — BASIC

Identify the voice and the agent in this sentence: "The cake was baked by my grandmother."

PROBLEM 3 — INTERMEDIATE

Identify the voice, the agent, and explain whether the agent is stated or missing: "Mistakes were made during the experiment."

PROBLEM 4 — APPLIED

Read this pair of sentences from a student's essay and decide which uses passive voice. Then rewrite the passive sentence in active voice: (A) "The committee selected three finalists." (B) "The award was presented by the principal at the assembly."

PROBLEM 5 — CRITICAL THINKING

Consider this news headline: "Funding for the arts program has been cut." Why might the writer have chosen passive voice here? What effect does the missing agent have on the reader? How would the meaning shift if the agent were included?

SUMMARY

Lesson Summary

In active voice, the agent (the doer of the action) serves as the grammatical subject of the sentence: "The dog chased the cat." In passive voice, the receiver of the action becomes the subject, and the verb follows the formula form of "to be" + past participle: "The cat was chased by the dog." To identify the agent in a passive sentence, look for the "by" phrase. If no "by" phrase is present, the sentence is an agentless passive, and the doer remains unstated.

Remember the decision steps: first, check for the "be" + past participle pattern to determine voice. Second, if it's passive, scan for a "by" phrase to identify the agent. Both voices are valuable tools — active voice for direct, action-oriented writing, and passive voice when the action or receiver matters more than the doer. Choosing voice intentionally makes you a stronger, more strategic writer.