Passive voice is one of the most important—and sometimes confusing—grammar points in English. It changes the focus of a sentence by shifting attention away from the person or thing doing the action (the subject) and toward the person or thing receiving the action (the object). Understanding how and when to use the passive voice will make your English more flexible, especially in formal writing, academic contexts, and everyday communication.
1. What Is the Passive Voice?
In English, sentences are usually written in the active voice:
- The teacher explained the lesson.
Here, the subject (the teacher) performs the action (explained).
In the passive voice, the structure changes:
- The lesson was explained (by the teacher).
Now, the focus is on the lesson, not the teacher. The doer of the action may be included (by the teacher) or omitted.
2. Basic Structure of the Passive Voice
The passive voice follows this structure:
Subject + form of “be” + past participle (+ by + agent)
Example:
- The cake was eaten by the children.
Breakdown:
- Subject: The cake
- “Be” verb: was
- Past participle: eaten
- Agent: by the children
3. Forming the Passive in Different Tenses
The passive voice can be used in almost all tenses. The key is to change the form of the verb “be” while keeping the past participle.
Present Simple
- Active: They clean the room.
- Passive: The room is cleaned.
Past Simple
- Active: She wrote the letter.
- Passive: The letter was written.
Future Simple
- Active: They will finish the project.
- Passive: The project will be finished.
Present Continuous
- Active: They are building a house.
- Passive: A house is being built.
Present Perfect
- Active: He has completed the work.
- Passive: The work has been completed.
Notice how “be” changes:
- is / was / will be / is being / has been
4. When to Use the Passive Voice
1. When the Doer Is Unknown
Sometimes we don’t know who did the action.
- My bike was stolen.
(We don’t know who stole it.)
2. When the Doer Is Not Important
The result matters more than who did it.
- The road was repaired yesterday.
3. When the Doer Is Obvious
Everyone already knows who performed the action.
- The suspect was arrested.
(It’s obvious the police did it.)
4. In Formal or Academic Writing
The passive voice is often used to sound more objective.
- The experiment was conducted under controlled conditions.
5. To Emphasize the Result
The passive highlights what happened rather than who did it.
- The window was broken during the storm.
5. Using “By” to Show the Doer
In passive sentences, the doer (agent) can be added using “by”:
- The book was written by the author.
- The song was performed by the band.
However, this part is often omitted if it’s not important:
- The book was written.
- The song was performed.
6. Verbs That Commonly Use the Passive
Some verbs are frequently used in passive constructions, especially in formal English:
- is made
- is known
- is called
- is believed
- is considered
Examples:
- He is known for his kindness.
- This dish is made with fresh ingredients.
- She is considered a great leader.
7. Passive with Modal Verbs
Passive voice can also be used with modal verbs like can, must, should, may.
Structure:
modal + be + past participle
Examples:
- The work must be finished.
- The rules should be followed.
- This problem can be solved.
8. Passive with “Get”
In informal English, “get” is sometimes used instead of “be”:
- He got hurt.
- They got married.
- The window got broken.
This form often suggests something unexpected or accidental.
9. Common Mistakes
Mistake 1: Wrong Verb Form
❌ The cake was eat.
✅ The cake was eaten.
Always use the past participle.
Mistake 2: Missing “Be” Verb
❌ The homework finished.
✅ The homework was finished.
The “be” verb is essential.
Mistake 3: Overusing Passive Voice
Too much passive voice can make writing unclear or boring.
❌ The decision was made, and the plan was created, and the work was done.
✅ They made the decision, created the plan, and did the work.
Use passive when needed—but not always.
10. Active vs Passive: Choosing the Right One
Active is better when:
- You want clarity and directness
- The subject is important
Example:
- The manager approved the plan.
Passive is better when:
- The action/result is more important
- The subject is unknown or irrelevant
Example:
- The plan was approved.
11. Special Passive Structures
1. “It is said that…”
Used for reporting general opinions.
- It is said that he is very rich.
- It is believed that the story is true.
2. “Have something done”
Used when someone does something for you.
- I had my hair cut.
- She had her car repaired.
This is technically a passive meaning.
12. Practice Examples
Convert active to passive:
- They built the bridge in 1990.
→ The bridge was built in 1990. - Someone stole my phone.
→ My phone was stolen. - The chef is preparing the meal.
→ The meal is being prepared. - They will announce the results tomorrow.
→ The results will be announced tomorrow.
13. Summary
The passive voice is formed with:
Subject + be + past participle
It is used when:
- The doer is unknown, unimportant, or obvious
- You want to emphasize the result
- You are writing formally
While it is a powerful tool, it should be used carefully. Too much passive voice can make your writing less clear, but using it correctly can make your English sound more natural and sophisticated.
以下は上記の内容の日本語訳です：
受動態は、英語の中でも非常に重要でありながら、時に理解が難しい文法項目です。受動態を使うことで、文の焦点を「動作を行う人（主語）」から「動作を受ける人・物」に移すことができます。この考え方を理解すると、英語表現の幅が広がり、特にフォーマルな文章やアカデミックな場面で役立ちます。
1. 受動態とは何か
英語の文は通常、「能動態（Active Voice）」で書かれます。
- The teacher explained the lesson.
（先生が授業を説明した）
この文では、「the teacher（先生）」が動作を行っています。
一方、「受動態（Passive Voice）」では次のようになります：
- The lesson was explained (by the teacher).
（授業は（先生によって）説明された）
ここでは、「the lesson（授業）」が主語となり、動作の受け手に焦点が当たっています。「誰が行ったか」は省略することもできます。
2. 受動態の基本構造
受動態の形は次の通りです：
主語 + be動詞 + 過去分詞 (+ by + 行為者)
例：
- The cake was eaten by the children.
（ケーキは子供たちに食べられた）
内訳：
- 主語：The cake
- be動詞：was
- 過去分詞：eaten
- 行為者：by the children
3. 時制ごとの受動態
受動態はほぼすべての時制で使えます。「be動詞」を時制に合わせて変えることがポイントです。
現在形
- Active: They clean the room.
- Passive: The room is cleaned.
（部屋は掃除される）
過去形
- Active: She wrote the letter.
- Passive: The letter was written.
（手紙は書かれた）
未来形
- Active: They will finish the project.
- Passive: The project will be finished.
（プロジェクトは終えられる）
現在進行形
- Active: They are building a house.
- Passive: A house is being built.
（家は建てられている最中だ）
現在完了形
- Active: He has completed the work.
- Passive: The work has been completed.
（仕事は完了している）
4. 受動態を使う場面
① 行為者が分からない場合
- My bike was stolen.
（自転車が盗まれた）
② 行為者が重要でない場合
- The road was repaired yesterday.
（道路は昨日修理された）
③ 行為者が明らかな場合
- The suspect was arrested.
（容疑者は逮捕された）
④ フォーマル・学術的な文
- The experiment was conducted under controlled conditions.
（実験は管理された条件で行われた）
⑤ 結果を強調したい場合
- The window was broken during the storm.
（窓は嵐の間に壊れた）
5. 「by」を使った行為者の表現
- The book was written by the author.
（その本は作者によって書かれた）
ただし、多くの場合は省略されます：
- The book was written.
（その本は書かれた）
6. よく使われる受動表現
- is made（作られる）
- is known（知られている）
- is called（呼ばれている）
- is believed（信じられている）
- is considered（考えられている）
例：
- He is known for his kindness.
（彼は親切で知られている）
7. 助動詞と受動態
構造：
助動詞 + be + 過去分詞
例：
- The work must be finished.
（仕事は終えられなければならない） - The rules should be followed.
（ルールは守られるべきだ）
8. 「get」を使う受動表現
口語では「be」の代わりに「get」を使うことがあります：
- He got hurt.（彼はけがをした）
- The window got broken.（窓が壊れた）
予期しない出来事を表すことが多いです。
9. よくある間違い
① 過去分詞の誤り
❌ was eat → ✅ was eaten
② be動詞の欠落
❌ The homework finished.
✅ The homework was finished.
③ 受動態の使いすぎ
受動態を多用すると分かりにくくなります。
10. 能動態と受動態の使い分け
能動態が良い場合
- 誰がしたかが重要
- 明確で直接的
例：
- The manager approved the plan.
受動態が良い場合
- 結果を強調したい
- 行為者が不明・不要
例：
- The plan was approved.
11. 特別な受動構文
① It is said that…
- It is said that he is rich.
（彼は金持ちだと言われている）
② have + 目的語 + 過去分詞
- I had my hair cut.
（髪を切ってもらった）
12. 練習問題
能動態 → 受動態に変えましょう：
- They built the bridge in 1990.
→ The bridge was built in 1990. - Someone stole my phone.
→ My phone was stolen. - The chef is preparing the meal.
→ The meal is being prepared. - They will announce the results tomorrow.
→ The results will be announced tomorrow.
13. まとめ
受動態の基本形：
主語 + be動詞 + 過去分詞
使う場面：
- 行為者が不明・不要
- 結果を強調したい
- フォーマルな文体
受動態は便利ですが、多用しすぎると分かりにくくなるため、能動態とのバランスが大切です。
