🌤️ 文法ジャンル別の解き方
TOEIC Part5「仮定法」の解き方と頻出パターン｜練習10問つき
仮定法の問題は、if 節と主節の時制の組み合わせを覚えていれば機械的に解けます。TOEICでは if の省略による倒置（Should you have ~ / Had we known ~）もよく出ます。
解き方のポイント
- 現在の事実に反する仮定：If + 過去形, 主語 + would + 原形
- 過去の事実に反する仮定：If + had + 過去分詞, 主語 + would have + 過去分詞
- 未来の可能性：If + 現在形, 主語 + will + 原形（ふつうの条件文）
- 倒置：Should you have any questions, ...（If you should have ~）
- 倒置：Had we known earlier, ...（If we had known ~）
ひっかけ注意
- 条件を表す if 節の中では未来のことも現在形（if it rains tomorrow）
- Were it not for ~ / Without ~（〜がなければ）
- unless は if not の意味。仮定法とは別に使う
例文で確認
| Should you have any questions, please contact us. | If 省略の倒置 → Should |
| Had the shipment arrived on time, we would have met the deadline. | 過去の反実仮想の倒置 → Had |
| If the weather is good tomorrow, the event will be held outdoors. | 条件の if 節は現在形 |
練習問題（10問）
選択肢をタップすると正解がわかります。動画では先生が解答と解説をしてくれます。
Q1. If the budget ___ approved, the project will begin in April.
答えと解説を見る
正解: A) is
The 'if' clause is a conditional adverbial clause, and even when it refers to a future event, it uses the present tense. So 'is' is correct. 'Were' is the subjunctive past, used for something contrary to fact, and clashes with the realistic context of 'starting in April'. 'Being' and 'to be' can't serve as a finite main verb.
Q2. It is essential that every employee ___ the safety guidelines.
答えと解説を見る
正解: B) follow
'It is essential that...' expresses necessity or a demand, and the that-clause following such expressions uses the base form of the verb regardless of the subject's person (the subjunctive mood). So 'follow' is correct. Essential, necessary, important, and verbs like suggest, recommend, and request all trigger the same pattern. 'Follows' (third person) and 'followed' (past) look correct in an ordinary sentence, but this construction calls for the base form.
Q3. The auditor requested that all financial records ___ available for review.
答えと解説を見る
正解: B) be
Verbs expressing demand or suggestion — request, suggest, recommend, insist, and others — are followed by a that-clause whose verb takes the base form (the subjunctive mood). So 'be' is correct. 'Are' and 'were' carry ordinary tense and don't fit this construction. 'Being' is a participle and can't serve as the main verb. This follows the same pattern as 'It is essential that...'.
Q4. The printer will jam if you ___ too much paper.
Q5. If the brakes ___ again, bring the bike back within the week.
答えと解説を見る
正解: A) malfunction
A first-conditional if-clause uses the present tense: 'malfunction'.
Q6. If the office ___ closer to home, Mr. Park would walk to work.
Q7. If the shipment ___ delayed, please notify the client immediately.
答えと解説を見る
正解: B) is
A real future condition uses the present tense in the if-clause: 'is'.
Q8. The launch would be delayed ___ the software fail final testing.
Q9. If the delivery ___ late again, the supplier contract will be reviewed.
答えと解説を見る
正解: B) arrives
A first-conditional if-clause uses the present tense: 'arrives'.
Q10. If the weather ___ fine this weekend, the block party will move outdoors.
答えと解説を見る
正解: C) stays
A first-conditional if-clause uses the present tense: 'stays'.