慶英会 塾長｜慶應義塾大学卒・英検1級
中高一貫校の学校英語・NEW TREASURE・英検対策を専門とするオンライン個別指導塾です。塾長紹介
結論：英検1級の意見英作文で仮定法や条件節を使う場合は、現在の現実的な条件・実現していない仮定・過去の反実仮想を分けます。たとえば If the city had invested … , it might have … は過去の仮定であり、効果が実際に生じたという証明ではありません。慶英会では独自36問の修正英文・全解説・200〜240語の模範意見英作文2篇を無料公開しました。
英検1級のWritingは英文要約1題と意見論述1題で、意見論述は200〜240語です。公式の評価観点は内容・構成・語彙・文法。英検協会・1級の試験形式とWriting評価観点をご確認ください。以下の36問は慶英会が作成した練習用例文で、英検協会の公式文法問題ではありません。
仮定法・条件節を正確に使う4つのルール
- 現実的な条件：If the plan succeeds, … のように、未来の条件でも通常if節は現在形を使う。
- 現在の反実仮想：If the service were available, it could … は現実と距離を置いた仮定を示す。
- 過去の反実仮想：If officials had checked …, they might have … は過去に起きなかったことを仮定する。
- only if / unless / even if：必要条件・例外・譲歩条件を区別する。仮定表現を使ったからといって結果を保証しない。
この演習は時制の形だけでなく、may / might / would / could の確実性、仮定と実績の区別、政策提案の条件まで確認します。修正例は一つの自然な書き方であり、別の文脈では複数の正答があり得ます。
独自36問｜条件節と仮定法を修正する問題編
現在・未来の条件｜ifとwillの混同
Q1：If the city will expand the route, more residents might travel.
Q2：If the council approves the plan, every resident benefits immediately.
Q3：The policy would help everyone if everyone would use the platform.
Q4：If more reliable information is available, officials would be able to compare options.
Q5：If a policy has costs, it definitely fails.
Q6：If the new system reduces errors, it has already been proved successful.
現在の反実仮想｜If … were, would …
Q7：If every student has a reliable connection, online lessons would reach them all.
Q8：If the service was entirely free, more families could use it.
Q9：If I am the mayor, I would compare several policy options.
Q10：The city might expand the programme if there will be no maintenance costs.
Q11：If the system were perfect, it will remove every barrier.
Q12：If all public needs were identical, one policy could serve everyone. This is already true.
過去の反実仮想｜If … had …, would have …
Q13：If officials had checked the data, they will have found the error.
Q14：The programme would have succeeded if the city invests more funds last year.
Q15：If the warnings reached everyone, every person would have evacuated safely.
Q16：Had the study included a comparison group, researchers will know the exact cause.
Q17：Without the pilot, the council would not know anything.
Q18：If the library had stayed closed, all students would have failed.
unless・only if・even ifの意味を逆にしない
Q19：Unless the programme succeeds, it should expand nationwide.
Q20：Only if staff are trained, the service may be introduced.
Q21：Even if some people cannot access the platform, that proves the entire policy useless.
Q22：Although the policy is effective, it might prove effective in the future.
Q23：The government should expand the project provided that the full benefits are absolutely certain.
Q24：Unless data improve, the result is always accurate.
仮定と実証を混同しない｜論理の飛躍
Q25：The city could save money with online forms, so it has saved money already.
Q26：If users received clearer information, they would definitely understand every procedure.
Q27：The project might improve access; therefore it has proved fair to everyone.
Q28：If subsidies were introduced, all firms would expand immediately.
Q29：The trial would have produced a different result, proving the existing policy failed.
Q30：The study did not include older people, so it proves the policy would not help them.
反論・提案・結論の条件を正確にする
Q31：If critics disagreed, the government must abandon the policy.
Q32：Even if the programme is expensive, its benefits will always outweigh costs.
Q33：If a pilot was encouraging, it should definitely be expanded everywhere.
Q34：Had the authorities used artificial intelligence, they would have prevented every mistake.
Q35：If the system cannot help everyone, it must never be used.
Q36：If the evidence remained uncertain, no decision could ever be made.
全36問の改善英文と文法・論理の理由
現在・未来の条件｜ifとwillの混同｜解答
Q1 修正例：If the city expands the route, more residents might be able to travel.
解説：通常の現実的なif条件節には現在形を用い、帰結にmightで可能性を残す。
Q2 修正例：If the council approves the plan, some residents may gain easier access.
解説：if節は適切でも、every/immediatelyを根拠なく断定しない。
Q3 修正例：The policy could help some residents if they were able to use the platform.
解説：仮定的な提案に合わせ、対象を限定する。
Q4 修正例：If more reliable information becomes available, officials will be better able to compare options.
解説：現実的な今後の条件と帰結の整合性を保つ。willでもmayでも文脈に合わせて使える。
Q5 修正例：If a policy has substantial costs, its benefits should be evaluated alongside those expenses.
解説：費用の存在だけで失敗を保証しない。
Q6 修正例：If the new system reduces errors, that would be encouraging, but a broader evaluation is still needed.
解説：未来の仮定をすでに完了した実証に変えない。
現在の反実仮想｜If … were, would …｜解答
Q7 修正例：If every student had a reliable connection, online lessons might become more accessible.
解説：現実の全員接続を前提にできない仮定。had＋mightで非現実的な仮定を示す。
Q8 修正例：If the service were entirely free, more families might be able to use it.
解説：仮定の距離を示すwere。口語でwasもあるが正式な作文ではwereを選べる。
Q9 修正例：If I were the mayor, I would compare several policy options.
解説：現実の役職でない仮定はIf I were。
Q10 修正例：The city might expand the programme if there were no maintenance costs.
解説：維持費ゼロという仮定をwereで表現。
Q11 修正例：Even if the system were highly reliable, it would not necessarily remove every access barrier.
解説：perfectとeveryを避けつつ仮定・帰結をそろえ、論点を限定。
Q12 修正例：If all public needs were identical, one policy might be easier to design; in reality, needs often differ.
解説：仮定を現実の事実だと宣言しない。
過去の反実仮想｜If … had …, would have …｜解答
Q13 修正例：If officials had checked the data, they might have found the error.
解説：過去に起きなかった仮定にmight have＋過去分詞。発見を保証しない。
Q14 修正例：The programme might have performed better if the city had invested more funds last year.
解説：if＋過去完了、帰結might have performed。
Q15 修正例：Even if the warnings had reached everyone, some residents might still have lacked safe routes.
解説：到達だけで全員の避難は保証できない。過去の条件はhad reached。
Q16 修正例：Had the study included a comparison group, researchers might have reached a firmer conclusion.
解説：Had＋主語＋過去分詞はif省略の倒置。確実な原因特定は保証しない。
Q17 修正例：Without the pilot, the council might have had less evidence about practical problems.
解説：過去の仮定としてmight have hadとし、anythingの全面否定を避ける。
Q18 修正例：If the library had remained closed, students who relied on its facilities might have faced greater difficulties.
解説：一部への可能性に限定し、過去の仮定と帰結を合わせる。
unless・only if・even ifの意味を逆にしない｜解答
Q19 修正例：The programme should not expand nationwide unless reliable evaluation supports expansion.
解説：unlessの否定条件を取り違えない。
Q20 修正例：The service may be introduced only if staff are appropriately trained.
解説：only ifの条件を主節の後に置く自然な語順。前置すれば倒置もあり得る。
Q21 修正例：Even if some people face access barriers, the platform could still help others.
解説：even ifは譲歩条件で全面無効の証明ではない。
Q22 修正例：If the policy proves effective, officials could consider expanding it.
解説：まだ効力が未確定ならalthoughの既存事実として扱わずifを使う。
Q23 修正例：The government might expand the project provided that credible evidence justifies its costs and risks.
解説：provided thatは条件。絶対確実性という非現実的・未検証の断定は不要。
Q24 修正例：Unless data quality improves, the result may remain unreliable.
解説：unlessの条件に対する帰結を正しく表す。
仮定と実証を混同しない｜論理の飛躍｜解答
Q25 修正例：Online forms could reduce some administrative costs, but the actual savings require evaluation.
解説：couldを過去の実績として扱わない。
Q26 修正例：Clearer guidance could help some users, although comprehension would need to be tested.
解説：受け取ることと理解を分ける。
Q27 修正例：The project might improve access, but its fairness across different groups remains unverified.
解説：可能性から全員への公平性を証明しない。
Q28 修正例：Targeted subsidies might encourage some firms to invest, depending on their circumstances.
解説：政策仮定と全企業の即時行動を混同しない。
Q29 修正例：A different design might have produced a different result, but this counterfactual cannot by itself prove failure.
解説：観測していない反事実から確証を導かない。
Q30 修正例：The study excluded older people, so its findings cannot establish how well the policy would work for them.
解説：データ欠落は無効の証明でも有効の証明でもない。
反論・提案・結論の条件を正確にする｜解答
Q31 修正例：If critics raise substantive concerns, the government should examine them before deciding whether to proceed.
解説：批判の存在から中止の義務を導かない。
Q32 修正例：Even if the programme has substantial costs, it could be worthwhile if the benefits justify them.
解説：費用便益が実際に成立することを条件にする。
Q33 修正例：If a pilot produces encouraging results, wider trials may be justified after its limits are reviewed.
解説：試行の結果と全国展開の条件を区別。
Q34 修正例：AI tools might have reduced some errors under suitable conditions, but complete prevention cannot be assumed.
解説：反事実の確実性と万能性を避ける。
Q35 修正例：A system may still be useful for some users if appropriate alternatives protect those it cannot serve.
解説：全員への利益を唯一の評価軸としない。
Q36 修正例：When evidence remains incomplete, policymakers can consider limited trials, safeguards and the risks of inaction.
解説：不確実性と意思決定不能は同義ではない。
英検1級独自TOPIC2題｜200〜240語の模範意見論述
独自TOPIC 1｜Should governments test new digital services before expanding them?
自分の賛否と理由3つを考え、例示で仮定を使う際には結果を事実に変えていないか点検してください。
模範英作文1（201語）
I believe governments should test new digital services carefully before expanding them nationwide. Such tools can improve convenience, but their success depends on whether residents can use them and whether the expected benefits outweigh the costs.
First, small trials can reveal practical access barriers. If an online application were introduced without telephone support, some residents might struggle to complete it. Testing the service with different users would help officials identify problems before relying on it more widely.
Second, early evaluation can improve financial decisions. A platform might reduce routine administrative work, but maintenance and staff training could create additional expenses. If authorities compared these costs during a pilot, they would have a stronger basis for judging its overall value.
Third, carefully reported trials can support public accountability. Residents should know what was measured and which results remain uncertain. A rise in digital transactions should not automatically be interpreted as proof that everyone received appropriate assistance.
Critics may argue that testing delays urgent improvements. That concern is legitimate, and some services may need immediate action. Nevertheless, where limited trials are feasible, policymakers should use them to reduce avoidable risks. I support gradual expansion only when reliable evidence and suitable safeguards justify it.
独自TOPIC 2｜Should schools offer printed alternatives to digital learning platforms?
自分の賛否と理由3つを考え、例示で仮定を使う際には結果を事実に変えていないか点検してください。
模範英作文2（204語）
I believe schools should continue offering printed alternatives when students cannot use digital learning platforms reliably. Online resources may be useful, but their availability does not guarantee that every learner benefits equally.
First, printed materials can protect access. If a student lacked a reliable internet connection, being able to read essential explanations on paper would reduce the risk of missing important work. This does not mean that printed books are always better; it means that learning conditions differ.
Second, alternative formats can support effective teaching. A teacher might use online exercises for repeated practice while providing printed explanations for unfamiliar concepts. If schools evaluated students’ understanding rather than counting completed exercises alone, they could make better decisions about the resources needed.
Third, maintaining appropriate alternatives can improve fairness. Some students need assistive technology or clearer instructions, and a single platform may not meet every requirement. Schools should examine which barriers can be corrected and which call for additional support.
Critics may argue that maintaining both formats creates unnecessary costs. That concern deserves consideration. However, if a digital-only policy excluded students from essential learning, saving money would not be the only relevant outcome. I favour evidence-based choices that balance accessibility, educational value and financial responsibility.
仕上げ12判断｜何が実際に起きたかを区別
追加判断1：If the programme had worked, the city might have expanded it. → Expansion happened.
追加判断2：If access improves, some residents may benefit.
追加判断3：Had researchers used a control group, they would certainly have proved the cause.
追加判断4：Unless the service remains accessible, officials should reconsider expansion.
追加判断5：Even if the system works for many users, some may still need support.
追加判断6：If the device were cheap, everybody has already purchased it.
追加判断7：The decision would have been different if the evidence had been stronger.
追加判断8：The study suggested a benefit, so the programme has definitely succeeded.
追加判断9：A policy could be useful under specified conditions.
追加判断10：If the new rule is implemented, it has already been implemented.
追加判断11：Without further evaluation, uncertainty may remain.
追加判断12：An unreal condition automatically shows that the opposite is true in every case.
追加判断12問の解答
追加判断1：不適切。条件付きの仮定で実施の事実とは異なる。
追加判断2：適切。現実的な条件を限定した表現。
追加判断3：不適切。比較群があっても因果の完全な確証を保証しない。
追加判断4：適切。アクセスが維持されなければ再検討という条件。
追加判断5：適切。多くへの便益と一部への障壁は両立。
追加判断6：不適切。仮定と過去の実績を混同。
追加判断7：適切。過去の反実仮想として整合。
追加判断8：不適切。示唆から完全な確実性は導けない。
追加判断9：適切。可能性を示す限定表現。
追加判断10：不適切。未来の条件と完了した事実を混同。
追加判断11：適切。評価の不足により不確実性が残り得る。
追加判断12：不適切。仮定法の形だけで現実の全ての事実を特定できない。
7日間の復習ルート
- 1日目：Q1〜6で現実的なif節と帰結の確信度を復習。
- 2日目：Q7〜12で現在の反実仮想を修正。
- 3日目：Q13〜18で過去の仮定と事実を分ける。
- 4日目：Q19〜24でunless・only if・even ifを比較。
- 5日目：Q25〜30で仮定と実証の飛躍を修正。
- 6日目：Q31〜36と模範英作文1で政策の提案条件を練習。
- 7日目：模範英作文2と追加判断を解き、公式の未使用TOPICでも自作答案を書く。
よくある質問
仮定法を多く使えば高得点になりますか？
いいえ。難しい文法を使ったこと自体で点数が保証されるわけではありません。英検協会は内容・構成・語彙・文法で評価します。意味を正確に伝えるために必要な場面で使いましょう。
if節でwouldは絶対使えませんか？
通常の条件節では現在形がよく使われますが、丁寧な依頼や意志を表すwouldなど例外的な用法もあります。「ifの中ではwouldが絶対に不可能」と丸暗記しないでください。
現在の現実と異なる条件を示すときは必ずwereですか？
正式な作文ではIf I wereなどが一般的です。くだけた会話にはwasも使われます。書き言葉では意味・文体と節の整合を確認してください。
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慶英会 塾長｜慶應義塾大学卒・英検1級。中高一貫校の学校英語・NEW TREASURE・英検対策を専門としています。塾長の経歴・指導方針を確認する