English Passive Voice: When and How to Use It | 英文被動語態完整指南

Every English learner in Taiwan hits the same wall. You know what passive voice is — you’ve seen it in grammar books a hundred times — but you still freeze when you need to actually use it. The problem isn’t that passive voice is hard. It’s that most courses drill the formula without explaining なぜ native speakers reach for it. According to Cambridge Grammar data, passive constructions appear in roughly 25% of all written English text. That’s not a minor footnote in the grammar syllabus — it’s a core pattern that shows up constantly in news reports, academic papers, business emails, and professional presentations.

What Is the Passive Voice? [英文被動語態是什麼？]

In English, every sentence has a voice — either active (主動語態) or passive (被動語態). In the active voice, the subject performs the action. In the passive voice, the subject receives the action instead.

Compare these two sentences:

• Active (主動): The manager signed the contract. → The manager is doing the signing.
• Passive (被動): The contract was signed by the manager. → The contract is the focus.

Both sentences contain the same facts, but the emphasis shifts completely. The passive voice moves the action — what happened to something — into the spotlight, while the doer steps back. This shift is not about being vague or evasive. It’s a deliberate choice that serves real communication purposes in English.

How to Form the Passive Voice [如何構成被動語態]

The formula is consistent across all tenses:

Subject + be (correct tense) + past participle (+ by + agent)

The agent (the person or thing that did the action) is introduced with “by” — but this part is often dropped when it’s irrelevant or obvious. Here’s how it looks across the most common tenses:

The “by + agent” element is optional. Include it only when the identity of the doer adds meaningful information. “The contract was signed by the CEO” matters. “The contract was signed by someone” does not.

Active vs Passive Voice [主動語態 vs 被動語態]

Here’s something most Taiwan grammar textbooks miss: native speakers almost always default to active voice in conversation and informal writing. The passive carries a more formal, sometimes impersonal tone — which is exactly right in certain situations, but sounds stiff and unnatural in others.

Think about how these register differently:

• Active (natural for conversation): “I left my keys on the table.” — direct, personal, clear.
• Passive (sounds odd in casual talk): “My keys were left on the table by me.” — awkward, overly formal, nobody talks like this.

But flip the context to a news report:

• Active (reads like gossip): “Police arrested the suspect at dawn.” — works, but names police as the subject.
• Passive (standard news style): “The suspect was arrested at dawn.” — the event is the focus, police are implied.

The key test: ask yourself whether naming the doer adds useful information. If yes, active. If no — or if the doer is unknown — passive is your tool.

For deeper practice with related grammar patterns, see this guide on English conditional sentences — another structure where choosing the right form changes your entire meaning.

When Should You Use the Passive Voice? [什麼時候使用被動語態？]

Passive voice earns its place in four main situations. Once you recognize these, you’ll start spotting them everywhere in English text:

1. When the doer is unknown
“My wallet was stolen on the MRT.” → You don’t know who stole it. Naming a non-existent subject (“Someone stole my wallet”) is less natural when the doer is genuinely anonymous.

2. When the doer is obvious from context
“The patient was diagnosed with hypertension.” → In a medical context, it’s understood a doctor made the diagnosis. Saying “The doctor diagnosed the patient” adds no new information — it just clutters the sentence.

3. In formal and academic writing
Academic papers deliberately use passive to sound objective. “The samples were collected over three months and were analyzed using spectroscopy” reads as more scientific than “We collected samples for three months and analyzed them.” The Purdue OWL style guide recommends passive voice in scientific writing for precisely this reason.

4. In news and media reporting
Journalists reach for passive when they can’t or won’t name a source: “A decision was made to raise interest rates.” The passive hides the decision-maker without lying about the fact.

5. To avoid assigning blame
“Mistakes were made during the project” — this sentence, beloved by politicians, deliberately obscures who made the mistakes. It’s grammatically passive and rhetorically evasive.

Passive Voice Across All Tenses [各時態的被動語態]

One of the most common errors Taiwan learners make is pairing the wrong “be” form with the tense they want. Here’s a complete reference — every major tense in passive form:

Note: p.p. = past participle. For irregular verbs, the past participle is not always the same as the simple past. “Write → wrote → written” is one of the most commonly confused.

If you want to strengthen your overall grammar foundation, review how English relative clauses work — they connect ideas in complex sentences the same way passive constructions reframe who or what is central to the message.

Common Mistakes Taiwan Learners Make [台灣學習者常犯的錯誤]

These four errors come up repeatedly in writing samples from intermediate Taiwan learners. Check your own work against each one:

Mistake 1: Using the base verb instead of past participle
✗ “The book is write by J.K. Rowling.”
✓ “The book was written by J.K. Rowling.”

The be verb carries the tense. The main verb must always be the past participle — not the base form, not the simple past.

Mistake 2: Forgetting “been” in perfect tenses
✗ “The contract has signed.。」”
✓ “The contract has been signed.。」”

“Has signed” is active (present perfect). For passive, you need the full structure: has/have + been + past participle. Missing “been” is the single most frequent passive error in student writing.

Mistake 3: Overusing passive in casual conversation
Passive voice can make everyday speech sound stiff and unnatural. “My keys were left on the table by me” is grammatically correct but nobody says it. “I left my keys on the table” is clearer and more natural. Reserve passive for formal writing, news, academic contexts — not your daily conversations.

Mistake 4: Confusing passive with adjective + “be”
✗ Treating “She was tired” as passive voice.
✓ “Tired” here is an adjective, not a past participle acting in a passive construction.

True passive requires an action verb: “She was exhausted by the project” is passive. “She was tired” is a linking verb + adjective. The test: can you ask “Who or what did the action?” If yes, it’s passive. “Who tired her?” works — but “She was tired” usually isn’t answering that question.

Watch: Passive Voice Explained by BBC Learning English [影片教學]

BBC Learning English’s “What’s the passive voice?” is one of the clearest short explanations available. It covers the core concept in just a few minutes with real examples:

Practice: Convert These to Passive Voice [練習時間：改寫為被動語態]

The best way to lock in passive voice is to convert sentences yourself. Try these five before reading the answers:

1. The company designs new products every year.
2. They will announce the winner tomorrow.
3. Someone has stolen her bicycle.
4. The chef prepares fresh meals every morning.
5. The government has approved the new policy.

Answers (答案):

1. New products are designed by the company every year.
2. The winner will be announced tomorrow.
3. Her bicycle has been stolen.
4. Fresh meals are prepared every morning.
5. The new policy has been approved by the government.

Notice how sentence 3 drops “by someone” — it adds nothing. And sentence 2 drops “by them” for the same reason. Clean passive voice means keeping only the information that matters.

Putting It Together [綜合練習]

Passive voice is not something to fear — and not something to overuse. The formula (be + past participle) is fixed; the judgment call is knowing when the situation calls for it. Once you internalize the four main contexts — unknown doer, obvious doer, formal writing, news reporting — you’ll stop treating passive as a grammar test question and start using it as an actual writing tool.

The most direct path from knowing passive voice to using it naturally? Read authentic English text every day. News articles especially — the BBCニュース homepage alone will give you five real passive constructions before you finish the front page.

For learners ready to go beyond passive voice, the next grammar patterns worth studying are gerunds vs infinitives — another area where Taiwan learners frequently make the wrong choice without knowing why. The logic is similar: context determines which form fits, and reading authentic English is how you build that instinct.

情報源

1. Purdue OWL: Active Versus Passive Voice — Academic writing guidance on when to use passive constructions in formal and scientific writing.
2. British Council: Passive Voice Grammar Reference — Comprehensive grammar reference for English learners covering all passive tense forms.
3. Cambridge Dictionary: Passive Voice — Cambridge’s grammar reference with passive voice definitions, examples, and usage rules.