Grammar Rule in 30 Seconds
Transform direct yes/no questions into statements using 'if' or 'whether' while removing question-word order and auxiliary 'do'.
- Use 'if' or 'whether' to connect the reporting clause to the question. Example: 'He asked if I was ready.'
- Change question word order back to statement order (Subject + Verb). Example: 'Are you...?' becomes '...if I was.'
- Backshift the tense if the reporting verb is in the past. Example: 'Do you like...?' becomes '...if I liked.'
Overview
Reported Yes/No Questions（Yes/No疑問文の間接話法）は、日常会話からビジネス、学術的な報告まで、あらゆる高度なコミュニケーションにおいて不可欠なスキルです。ask, wonder, inquire など）を使いこなし、if や whether を適切に選択し、時制や代名詞を文脈に合わせて瞬時に調整する能力は、ネイティブスピーカーが持つ「情報のメタ化（客観視）」の感覚を共有することに他なりません。日本語では「〜かどうか尋ねた」という比較的シンプルな構造で済みますが、英語では語順の変更や時制の一致（Backshift）といった、日本語には存在しない厳格なルールが適用されます。本稿では、上級者が陥りやすい落とし穴や、文体による使い分け、そしてネイティブスピーカーが無意識に使い分けているニュアンスの差まで、徹底的に解説します。Subordinate Clause）」へと変化し、文全体の「目的語」としての役割を果たすようになる点です。このプロセスにおいて、日本語話者が最も意識すべきは「疑問文の解体と平叙文への再構築」です。- 1接続詞の導入:
ifまたはwhetherを用いて、「〜かどうか」という節を導きます。 - 2語順の正常化: 疑問文特有の「助動詞＋主語」の語順が解消され、「主語＋動詞」の平叙文の語順に戻ります。これは、その節がもはや直接的な「問い」ではなく、一つの「事実の報告」へと性質を変えたことを示しています。
- 3時制の一致 (Backshift): 報告する動詞（
askedなど）が過去形である場合、節内の動詞もそれに応じて過去側へシフトします。
“Are you hungry?” という直接疑問文を He asked で報告する場合、He asked if I was hungry. となります。ここで Are you が I was に変化している点に注目してください。日本語の感覚では「彼が、私がお腹が空いているか（どうか）聞いた」となり、節内の時制（空いている）は現在形のまま維持されることが多いですが、英語では「聞いた時点」に合わせて時制を後ろにずらす必要があります。この「時間軸の同期」が、英語における論理的整合性の鍵となります。ask: 最も一般的で汎用性が高い。wonder: 「〜かなと思う」「自問する」というニュアンス。want to know: 情報を強く求めている場合。inquire/enquire: 非常にフォーマル。公式な問い合わせなど。
if と whether の使い分けif: カジュアルから標準的な表現。日常会話で多用される。whether: よりフォーマル。また、or notを伴う場合や、選択肢が明確な場合に好まれる。前置詞の後ではwhetherしか使えません（例:It depends on whether...）。
asked 等）の場合、以下のルールに従います。“Do you like it?” | She asked if I liked it. |“Are you leaving?” | He asked if I was leaving. |“Did you see him?” | I asked if they had seen him. |“Have you finished?” | She wondered if I had finished. |will) | Conditional (would) | “Will it rain?” | They asked if it would rain. |can→couldmay→mightmust→had to(義務の場合)shall→should(提案や助言を求める場合)
here→therenow→then/at that timetoday→that daytomorrow→the next day/the following dayyesterday→the day before/the previous day
- ビジネスにおける丁寧な確認:
“Can you finish this by Friday?” と聞くよりも、“I was wondering if you could finish this by Friday.” と報告動詞（wonder）を過去進行形にして間接的に伝えることで、相手への心理的圧迫を減らし、非常に丁寧でプロフェッショナルな依頼になります。これは日本語の「〜していただけるかなと思いまして」という謙譲のニュアンスに近いものです。- 会議やプレゼンの要約:
“The client asked whether we had considered the environmental impact.” のように表現することで、質疑応答の内容を客観的な事実としてレポートに組み込むことができます。- 不確実性の表現:
“I wasn't sure if the office was open on Saturdays.” （土曜日にオフィスが開いているかどうか確信がなかった）。このように、過去の自分の思考プロセスを記述する際に不可欠です。- 社交的な距離感の維持:
“May I ask if you are the person in charge?” （担当の方かどうかお伺いしてもよろしいでしょうか）のように、間接話法をクッションとして使うことで、洗練された印象を与えます。- Bad:
She asked me if did I like the food. - Good:
She asked me if I liked the food.
if の後に did や do を残してしまうミスが多発します。間接疑問文は「疑問文ではなく肯定文の語順」であることを徹底してください。- Bad:
He asked if I am coming tomorrow. - Good:
He asked if I was coming the next day.
am をそのまま使いたくなります。しかし、英語では「聞いた」という過去の時点に視点を固定するため、過去形にする必要があります。if と whether の混同（特に前置詞の後）- Bad:
It depends on if they agree. - Good:
It depends on whether they agree.
if を置くのは不適切とされます。日本語ではどちらも「〜かどうか」で済んでしまうため、注意が必要です。if 節内での will の過剰使用- Bad:
I asked if he will help me. - Good:
I asked if he would help me.
would に変える必要があります。日本語の「〜してくれるか」に引きずられて will を残さないようにしましょう。that節) |if / whether | 疑問詞 (who, where, etc.) | that (省略可) |“Are you okay?” | “Where are you?” | “I am okay.” |...if I was okay. | ...where I was. | ...that I was okay. |Wh-Questionの場合も語順は「主語＋動詞」になりますが、接続詞としてifではなく疑問詞をそのまま使います。that節は単なる「事実」を伝えますが、if/whether節は「不確実なこと・問い」を伝えます。この「不確実性」こそがif/whetherの本質です。
if と whether で、or not をつける位置に決まりはありますか？whether の場合は、whether or not I should go と whether I should go or not の両方が可能です。また、whether or not と繋げて使うことも多いです。一方、if の場合は、if or not と繋げることはできず、必ず節の最後に or not を置くか、あるいは or not 自体を省略します。He asked if the Earth is round. は、地球が丸いという事実は変わらないため、現在形でも間違いではありません。しかし、試験やフォーマルなライティングでは、原則通り過去形にするのが最も安全です。whether しか使えないケースを具体的に教えてください。- 1前置詞の直後:
We talked about whether we should stay. - 2不定詞
to doが続く場合:I don't know whether to accept the offer.(if to acceptとは言えません) - 3節が文の主語になる場合:
Whether he will come is still uncertain.
say を使って He said if... と言えますか？say は事実を述べる動詞であり、疑問を導入することはできません。疑問を報告する場合は必ず ask, wonder, want to know などの「問い」に関連する動詞を使用してください。これは上級者でも時折間違えるポイントです。3. Tense Backshift in Reported Questions
| Direct Tense | Direct Example | Reported Tense | Reported Example |
|---|---|---|---|
|
Present Simple
|
Do you stay?
|
Past Simple
|
He asked if I stayed.
|
|
Present Continuous
|
Are you staying?
|
Past Continuous
|
He asked if I was staying.
|
|
Past Simple
|
Did you stay?
|
Past Perfect
|
He asked if I had stayed.
|
|
Present Perfect
|
Have you stayed?
|
Past Perfect
|
He asked if I had stayed.
|
|
Will
|
Will you stay?
|
Would
|
He asked if I would stay.
|
|
Can
|
Can you stay?
|
Could
|
He asked if I could stay.
|
Meanings
The method of reporting a question that has a 'yes' or 'no' answer without using the exact words of the speaker, typically requiring a change in tense and word order.
Standard Reporting
Relaying a simple inquiry from one person to another.
“He asked if I had seen his keys.”
“They wondered whether it would rain during the ceremony.”
Formal Alternatives
Using 'whether' to present two or more distinct possibilities or to maintain a professional tone.
“The board inquired whether the budget was sufficient or if more funds were required.”
“It remains to be seen whether the policy will be effective.”
Infinitive Choice
Using 'whether' (but not 'if') followed by a 'to-infinitive' to express a decision between options.
“I didn't know whether to laugh or cry.”
“She was debating whether to accept the offer.”
Reference Table
| 直接疑問文 (Direct) | 報告された疑問文 (Reported) | 主な変更点 |
|---|---|---|
|
"Are you ready?"
|
She asked if I was ready.
|
時制を過去へ、語順を肯定文に、ifを挿入。
|
|
"Did you enjoy the movie?"
|
He wondered whether I had enjoyed the movie.
|
過去形から過去完了へ、選択肢を意識してwhetherを使用。
|
|
"Can she swim?"
|
They enquired if she could swim.
|
助動詞 can を could に変更、肯定文の語順。
|
|
"Have you finished?"
|
I asked if he had finished.
|
現在完了から過去完了へ変更。
|
|
"Will you help me?"
|
She asked whether I would help her.
|
未来の will を would に変更。
|
|
"Do you live here?"
|
He asked if I lived there.
|
Doを削除、現在形から過去形へ、hereをthereに。
|
|
"Is the cafe open?"
|
We wanted to know if the cafe was open.
|
現在形から過去形へ変更。
|
フォーマル度スペクトル
The coordinator inquired whether the delegate would be attending the summit. (Professional vs Casual)
He asked if the delegate was coming to the meeting. (Professional vs Casual)
He asked if they were coming. (Professional vs Casual)
He was like, 'You coming or what?' (Professional vs Casual)
Yes/No疑問文の報告ルール
キーワード
- if Introduces the reported question
- whether Alternative to 'if', often for choices or formality
動詞の変化
- 時制の一致 Change present to past, past to past perfect, etc.
- 助動詞の削除 Do, Does, Did are dropped
構造
- 肯定文の語順 Subject + Verb (not verb + subject)
- 報告の動詞 Asked, wondered, enquired, wanted to know
直接 vs 報告されたYes/No疑問文
間接疑問文の作り方フロー
Yes/Noで答える質問ですか？
報告する動詞は過去形ですか？
語順はどうなっていますか？
間接疑問文が使われる場面
フォーマルな場面
- • Zoomでの採用面接
- • 学術的なレポート
- • ビジネスメール
- • 会議での発言
カジュアルな会話
- • 友達とのチャット
- • カフェでの注文
- • ゲームのボイスチャット
- • SNSのコメント
情報の伝達
- • 議論の要約
- • 伝言の報告
- • 問い合わせ内容の説明
- • 噂話の共有
丁寧な表現
- • 控えめな質問
- • 依頼を和らげる
- • 不確実性の表現
- • 適切な距離感を保つ
レベル別の例文
He asked if I was cold.
She asked if you like pizza.
I asked if he is here.
They asked if we have a car.
He asked if I wanted some water.
She wondered if it was raining.
They asked if I could swim.
I asked if she had a brother.
The teacher asked if we had finished the homework.
I asked whether the train was on time.
She wanted to know if I would be at the party.
He asked if I had ever been to France.
The manager inquired whether I was available for an interview.
I asked if they had been waiting long before I arrived.
She asked whether I preferred the red one or the blue one.
They wondered if the project would be completed by Friday.
The committee questioned whether the findings were statistically significant.
I was unsure whether to confront him about the discrepancy.
There was some debate as to whether the new law would actually reduce crime.
She asked if I might have overlooked the most obvious solution.
The philosopher pondered whether existence precedes essence in all cases.
It is highly debatable whether such a radical shift in policy is even feasible.
The witness was asked whether he could definitively swear to the defendant's presence.
One might ask whether the ends truly justify the means in this instance.
間違えやすい
Learners confuse 'if' as a question linker with 'if' as a conditional marker.
Learners often use 'that' to report questions.
よくある間違い
He asked me if am I okay.
He asked me if I was okay.
She asked if you like pizza?
She asked if you liked pizza.
I asked if did he go.
I asked if he went.
They asked if I have seen it.
They asked if I had seen it.
We discussed if we should go.
We discussed whether we should go.
文型パターン
I was wondering if ___.
It depends on whether ___ or not.
Real World Usage
They asked whether I had experience with Python.
She asked if I'm coming tonight.
I inquired whether the item was still in stock.
We examined whether the results were consistent.
The judge asked if the witness was telling the truth.
I asked if breakfast was included.
時制の一致（Backshifting）を忘れずに
She asked if I was ready.
語順のトラップに注意！
She asked if was he coming?と言わないように気をつけて！ 正解は：
She asked if he was coming.
If と Whether の使い分け
He asked whether I wanted coffee or tea.
英語での丁寧なニュアンス
I wondered if you could help me.
Do/Does/Did はサヨナラ
He asked if I liked pizza.
Smart Tips
Try adding 'or not' at the end. If it sounds natural, 'whether' is usually the better choice.
Always check your pronouns. 'Are you coming?' asked by John to me becomes 'if I was coming'.
発音
Falling Intonation
Unlike direct questions which often rise at the end, reported questions have falling intonation because they are grammatically statements.
Statement Fall
She asked if I liked it. ↘
Conveys that this is a piece of reported information, not a direct question.
暗記しよう
記憶術
Remember 'I.F.' — Indirect Form. If it's indirect, the 'If' comes first, and the 'Form' is a statement.
視覚的連想
Imagine a bridge made of the words 'IF' and 'WHETHER' connecting two islands. On the first island, people are shouting questions with 'Do' and 'Are'. As they cross the bridge, they drop their 'Do' signs and stand in a straight line (statement order) on the second island.
Rhyme
When 'do' and 'does' are in the way, throw them out and 'if' will stay!
Story
A detective is interviewing a witness. The witness says 'Did you see him?' The detective writes in his notebook: 'He asked if I had seen him.' The detective always turns questions into facts for his report.
Word Web
チャレンジ
Think of three questions you were asked today. Write them down as reported questions using 'if' or 'whether'.
文化メモ
British speakers are slightly more likely to use 'whether' in semi-formal situations compared to American speakers, who favor 'if' more broadly.
In global academic English, 'whether' is used to maintain an objective, detached tone, avoiding the conditional 'if' which can sometimes imply a 'supposition' rather than a 'question'.
The word 'whether' comes from the Old English 'hwæther', which specifically meant 'which of two'.
会話のきっかけ
Has anyone ever asked you if you wanted to move to another country?
Can you tell me whether you prefer working in the morning or at night?
日記のテーマ
よくある間違い
Test Yourself
My friend wanted to know ___ I had finished the report.
Find and fix the mistake:
She asked if was he coming to the meeting.
Translate into English: 'Ella me preguntó si yo había visto su teléfono.'
Answer starts with: ["S...
Choose the correct sentence:
Score: /4
練習問題
8 exercisesHe asked me...
Find and fix the mistake:
She asked if did I see the keys.
We discussed ___ to buy a new car.
He wondered...
1. 'Is he here?' 2. 'Does he stay?' 3. 'Can he go?'
I asked him if or not he was coming.
A: 'Did you finish?' B: 'What did he ask?' C: 'He asked...'
asked, wondered, said, inquired
Score: /8
Practice Bank
11 exercisesThe interviewer ___ whether I had previous experience.
My colleague wondered if he could to help me.
Choose the correct sentence:
Translate into English: 'El jefe preguntó si el informe estaba listo.'
Arrange these words into a sentence:
Match the direct questions with their reported forms:
I wasn't sure if she ___ (know) the answer.
He asked whether do you need any help.
Choose the correct sentence:
Translate into English: 'Ella se preguntaba si el paquete llegaría a tiempo.'
Arrange these words into a sentence:
Score: /11
よくある質問 (8)
In most cases, they are interchangeable. However, `whether` is more formal and is required after prepositions and before infinitives.
If the reporting verb is in the past, backshifting is standard. However, if the situation is still true (e.g., 'He asked if I live in London'), you can sometimes keep the present tense.
No, 'if or not' is generally considered incorrect. Use `whether or not` or just `if` by itself.
Because those are question auxiliaries used for inversion. Since reported questions are statements, they don't need question auxiliaries.
No. 'Asked that' is used for requests (subjunctive), not for reporting questions. Use `asked if`.
Only if the main clause is a question, e.g., 'Can you tell me if he's coming?' If the main clause is a statement, use a period.
You can use `wonder`, `inquire`, `want to know`, `query`, or `question`.
Historically yes, but now it's used for any yes/no question, even if only one option is mentioned.
Scaffolded Practice
1
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
si
English requires a shift to statement word order; Spanish is more flexible.
ob
German verb placement rules are even stricter than English.
si
French 'si' elides to 's' before 'il' (s'il), whereas English 'if' never changes.
〜かどうか (~ka dou ka)
The marker comes at the end of the clause in Japanese, but at the beginning in English.
ما إذا (ma idha)
Arabic often maintains the question particle within the indirect structure.
是否 (shìfǒu)
Chinese has no tense backshifting, which is a major hurdle for learners.
Learning Path
Prerequisites
Learn These First
関連動画
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