なぜやるか
ペア表現とは、必ず2つの語がセットで使われる表現のことです。TOEIC では both…and / either…or / neither…nor / not only…but also の基本4パターンに加え、so…that / whether…or / not…but / A rather than B という発展パターンも頻出します。
600点以上の壁では、次のポイントで差がつきます。
- シグナル語を先に見つける：空所の後ろにある and / or / nor / but also / that / but などから前の語を逆算する
- 動詞の一致：both A and B は複数扱い、either / neither / not only は B に一致
- Not only の倒置：文頭に出ると “Not only did S V…” の形になる
- so vs such：後ろが形容詞のみなら so、形容詞 + 名詞なら such
攻略法
パターン一覧（8種類）
| ペア表現 | 意味 | シグナル語 |
|---|---|---|
| both A and B | AもBも両方 | and |
| either A or B | AかBのどちらか | or |
| neither A nor B | AもBも〜でない | nor |
| not only A but also B | AだけでなくBも | but also |
| so + 形/副 + that SV | 非常に〜なので… | that（前にso） |
| whether A or B | AであろうとBであろうと | or（前にwhether） |
| not A but B | AではなくBだ | but（前にnot） |
| A rather than B | BよりむしろA | rather than |
見分け方（最重要）： 空所の前後のシグナル語を先に確認する。
重要ルール：動詞の一致
| ペア表現 | 動詞の一致 | 例 |
|---|---|---|
| both A and B | 複数（常に） | Both the CEO and the CFO are present. |
| either A or B | Bに一致 | Either the manager or the staff are responsible. |
| neither A nor B | Bに一致 | Neither the report nor the data is ready. |
| not only A but also B | Bに一致 | Not only the staff but also the director was informed. |
上級パターン①：Not only の倒置
文頭に Not only が置かれると、後ろの節で倒置が起きます。
通常： The project not only reduced costs but also improved quality.
倒置： Not only [did] the project reduce costs, but it also improved quality.
↑ 助動詞が主語の前に出る
見分け方： “Not only _ S V（原形）” → 空所は助動詞（did / is / has / was など）。
上級パターン②：so…that vs such…that
| 形 | 構造 | 例 |
|---|---|---|
| so | so + 形容詞/副詞 + that SV | The price was so high that no one bought it. |
| such | such + (a/an) + 形容詞 + 名詞 + that SV | It was such a high price that no one bought it. |
見分け方： 空所の後が「形容詞のみ」→ so、「形容詞 + 名詞」→ such。
上級パターン③：not A but B と A rather than B
“`
not A but B：The issue was [not] the budget [but] the schedule.
（問題は予算ではなくスケジュールだった）
A rather than B：We chose quality [rather than] speed.
（スピードよりむしろ品質を選んだ）
“`
rather than と instead of の違い：
– rather than → 後ろに動詞の原形・動名詞・名詞
– instead of → 後ろに名詞・動名詞（前置詞のため）
やり方
| ステップ | 内容 |
|---|---|
| 1 | 攻略法の表を読み、8つのパターンとシグナル語を確認する |
| 2 | 練習問題を解く（まず空所の前後のシグナル語を探す） |
| 3 | 間違えた問題は「どのシグナル語を見落としたか」を確認する |
| 4 | 正解できた問題も、構造把握まで読んで根拠を確認する |
16問以上正解（80%）を目標にしてください。
練習問題（20問）
Q1. The engineering team will assess ------- the structural integrity of the existing bridge and the feasibility of constructing an additional lane to handle the increased traffic volume.
(A) neither (B) both (C) either (D) not only
Q1の解答・解説を見る
- (A) neither → “neither A and B” は不可。neither の後は “nor” が必要
- (C) either → “either A and B” は不可。either の後は “or” が必要
- (D) not only → “not only A and B” は不可。not only の後は “but also” が必要
S[The engineering team] V[will assess] both the structural integrity (of the existing bridge) and the feasibility (of constructing an additional lane) (to handle the increased traffic volume).
Q2. Not only ------- the company reduce its operational costs following the restructuring plan, but it also expanded its product lineup by partnering with three international suppliers.
(A) is (B) has (C) was (D) did
Q2の解答・解説を見る
- (A) is → 現在形の be 動詞。”Not only is the company reduce” は文法的に不成立
- (B) has → 現在完了の助動詞。後ろに原形の reduce が続く場合は did が適切
- (C) was → 過去形の be 動詞。”Not only was the company reduce” は文法的に不成立
Not only did S[the company] V[reduce] its operational costs (following the restructuring plan), but S[it] also V[expanded] its product lineup (by partnering (with three international suppliers)).
Q3. ------- the updated security protocol nor the newly installed monitoring system was sufficient to prevent unauthorized access to the company’s confidential client database.
(A) Both (B) Either (C) Neither (D) Not only
Q3の解答・解説を見る
- (A) Both → “both A nor B” は不可。both の後は “and” が必要
- (B) Either → “either A nor B” は不可。either の後は “or” が必要
- (D) Not only → “not only A nor B” は不可。not only の後は “but also” が必要
Neither the updated security protocol nor the newly installed monitoring system V[was sufficient] (to prevent unauthorized access (to the company’s confidential client database)).
Q4. It was ------- the cost of the renovation project but the unexpected delay in obtaining the necessary permits that caused the executive committee to reconsider the entire development plan.
(A) not (B) both (C) either (D) neither
Q4の解答・解説を見る
- (B) both → “both A but B” は不可。both の後は “and” が必要
- (C) either → “either A but B” は不可。either の後は “or” が必要
- (D) neither → “neither A but B” は不可。neither の後は “nor” が必要
It was not the cost (of the renovation project) but the unexpected delay (in obtaining the necessary permits) that V[caused] the executive committee (to reconsider the entire development plan).
Q5. Both the head of the research department and the lead data analyst ------- expected to present their findings at the upcoming international conference on sustainable energy development.
(A) is (B) was (C) has been (D) are
Q5の解答・解説を見る
- (A) is → 単数形。both A and B は常に複数扱いなので不可
- (B) was → 過去形の単数。both A and B には複数の動詞が必要
- (C) has been → 単数の現在完了。both A and B には合わない
S[Both the head (of the research department) and the lead data analyst] V[are expected] (to present their findings (at the upcoming international conference (on sustainable energy development))).
Q6. The volume of customer complaints regarding the new billing system was ------- high that the IT department was instructed to suspend the update and revert to the previous version immediately.
(A) such (B) so (C) very (D) too
Q6の解答・解説を見る
- “so high that…” → 形容詞のみなので so ✓
- “such a high volume that…” → 形容詞 + 名詞の構造なら such になる
- (A) such → “such high that” は不可。such の後は “(a/an) + 形容詞 + 名詞” が必要
- (C) very → very の後に that SV は続かない
- (D) too → “too…to do” の形をとる。”too…that” という構造は存在しない
S[The volume (of customer complaints) (regarding the new billing system)] V[was] so high that S[the IT department] V[was instructed] (to suspend the update and revert (to the previous version) immediately).
Q7. Vendors who have questions about the procurement process may contact the purchasing department ------- by sending an inquiry through the official supplier portal or by calling the dedicated procurement hotline.
(A) either (B) both (C) not only (D) neither
Q7の解答・解説を見る
- (B) both → “both A or B” は不可。both の後は “and” が必要
- (C) not only → “not only A or B” は不可。not only の後は “but also” が必要
- (D) neither → 否定の意味になり、連絡方法を説明する文脈に合わない
S[Vendors (who have questions (about the procurement process))] V[may contact] the purchasing department either by sending an inquiry (through the official supplier portal) or by calling the dedicated procurement hotline.
Q8. ------- the board approves the proposed merger or decides to postpone the decision until the next fiscal quarter, all shareholders will be notified within 24 hours of the final ruling.
(A) Although (B) Even if (C) Whether (D) Unless
Q8の解答・解説を見る
- (A) Although → 逆接の接続詞。”A or B” とのペア構造を作らない
- (B) Even if → “even if A or B” は文法的に成立するが、whether…or という確立したペア表現がある
- (D) Unless → 条件の接続詞。「〜でない限り」の意味で文脈に合わない
Whether S[the board] V[approves] the proposed merger or V[decides] (to postpone the decision (until the next fiscal quarter)), S[all shareholders] V[will be notified] (within 24 hours (of the final ruling)).
Q9. The company’s latest sustainability report has ------- highlighted the progress made in reducing greenhouse gas emissions but also outlined a comprehensive roadmap for achieving carbon neutrality by 2035.
(A) both (B) either (C) neither (D) not only
Q9の解答・解説を見る
- (A) both → “both A but also B” は不可。both の後は “and” が必要
- (B) either → “either A but also B” は不可。either の後は “or” が必要
- (C) neither → “neither A but also B” は不可。neither の後は “nor” が必要
S[The company’s latest sustainability report] V[has not only highlighted] the progress (made (in reducing greenhouse gas emissions)) but also V[outlined] a comprehensive roadmap (for achieving carbon neutrality (by 2035)).
Q10. The board of directors decided to focus on strengthening existing partnerships ------- than pursuing aggressive expansion into untested markets during the current period of economic uncertainty.
(A) rather (B) instead (C) more (D) other
Q10の解答・解説を見る
- (B) instead → “instead than” という表現は存在しない。instead of〜（前置詞 of が必要）
- (C) more → “more than”（〜以上）は数量の比較を表す。文脈に合わない
- (D) other → “other than”（〜以外に）は除外を表す。文脈に合わない
S[The board of directors] V[decided] (to focus (on strengthening existing partnerships) rather than pursuing aggressive expansion (into untested markets) (during the current period (of economic uncertainty))).
Q11. Neither the assistant store manager nor the sales associates ------- available to assist customers with the newly installed self-checkout terminals during the peak shopping hours on Saturday.
(A) was (B) has been (C) were (D) is
Q11の解答・解説を見る
- (A) was → 過去形の単数。B が複数（associates）なので不可
- (B) has been → 単数の現在完了。B が複数なので不可
- (D) is → 現在形の単数。B の数・時制と合わない
S[Neither the assistant store manager nor the sales associates] V[were available] (to assist customers (with the newly installed self-checkout terminals) (during the peak shopping hours (on Saturday))).
Q12. The research institute’s annual report not only documented the team’s groundbreaking discoveries in renewable energy ------- presented a detailed plan for commercializing the technology within the next five years.
(A) and also (B) but also (C) or instead (D) yet still
Q12の解答・解説を見る
- (A) and also → “not only A and also B” は標準的なペア表現ではない
- (C) or instead → “not only A or instead B” は不可
- (D) yet still → “not only A yet still B” は不可
S[The research institute’s annual report] V[not only documented] the team’s groundbreaking discoveries (in renewable energy) but also V[presented] a detailed plan (for commercializing the technology (within the next five years)).
Q13. Either the project manager or the senior engineers ------- responsible for reviewing all safety inspection reports before they are submitted to the regulatory authority for final approval.
(A) are (B) is (C) was (D) has been
Q13の解答・解説を見る
- (B) is → 単数形。B が複数（engineers）なので不可
- (C) was → 過去形の単数。B の数・時制と合わない
- (D) has been → 単数の現在完了。B が複数なので不可
S[Either the project manager or the senior engineers] V[are responsible] (for reviewing all safety inspection reports (before they are submitted (to the regulatory authority) (for final approval))).
Q14. The new airport terminal has proven to be ------- efficient that passenger processing times have decreased by nearly forty percent compared to the same period last year.
(A) such (B) very (C) too (D) so
Q14の解答・解説を見る
- “so efficient that…” → 形容詞のみなので so ✓
- “such an efficient terminal that…” → 形容詞 + 名詞の構造なら such になる
- (A) such → “such efficient that” は不可。such の後は “(a/an) + 形容詞 + 名詞” が必要
- (B) very → very の後に that SV は続かない
- (C) too → “too…to do” の形をとる。”too…that” という構造は存在しない
S[The new airport terminal] V[has proven] (to be so efficient that S[passenger processing times] V[have decreased] (by nearly forty percent) (compared (to the same period last year))).
Q15. The primary objective of the training program is ------- to evaluate employees’ current skill levels but to provide them with practical tools and strategies to enhance their professional performance.
(A) both (B) neither (C) not (D) either
Q15の解答・解説を見る
- (A) both → “both A but B” は不可。both の後は “and” が必要
- (B) neither → “neither A but B” は不可。neither の後は “nor” が必要
- (D) either → “either A but B” は不可。either の後は “or” が必要
S[The primary objective (of the training program)] V[is] not to evaluate employees’ current skill levels but to provide them (with practical tools and strategies) (to enhance their professional performance).
Q16. Customers are required to notify the service center in advance ------- they plan to pick up their repaired devices in person or prefer to have them delivered to the address on file.
(A) although (B) whether (C) unless (D) since
Q16の解答・解説を見る
- (A) although → 逆接の接続詞。”A or B” とのペア構造を作らない
- (C) unless → 条件の接続詞。「〜でない限り」の意味で文脈に合わない
- (D) since → 原因・理由の接続詞。「〜であるので」の意味で文脈に合わない
S[Customers] V[are required] (to notify the service center (in advance)) whether S[they] V[plan] (to pick up their repaired devices in person) or V[prefer] (to have them delivered (to the address on file)).
Q17. The success of the product launch was attributed ------- to the marketing campaign but to the exceptional customer service provided by the company’s dedicated support team throughout the entire process.
(A) not (B) both (C) either (D) neither
Q17の解答・解説を見る
- (B) both → “both A but B” は不可。both の後は “and” が必要
- (C) either → “either A but B” は不可。either の後は “or” が必要
- (D) neither → “neither A but B” は不可。neither の後は “nor” が必要
S[The success (of the product launch)] V[was attributed] not to the marketing campaign but to the exceptional customer service (provided (by the company’s dedicated support team) (throughout the entire process)).
Q18. The corporate policy requires all travel expense reports to be submitted within ten business days of the trip’s completion, ------- the expenses were incurred domestically or internationally.
(A) even though (B) unless (C) whether (D) provided that
Q18の解答・解説を見る
- (A) even though → 逆接の接続詞。「〜であるにもかかわらず」の意味で文脈に合わない
- (B) unless → 条件の接続詞。「〜でない限り」の意味で文脈に合わない
- (D) provided that → 条件の接続詞。「〜という条件で」の意味で文脈に合わない
S[The corporate policy] V[requires] all travel expense reports (to be submitted (within ten business days (of the trip’s completion))), whether the expenses V[were incurred] domestically or internationally.
Q19. Not only ------- the revised customer satisfaction survey provide more detailed insights into consumer preferences, but it also introduced a new rating system that made data analysis significantly easier for the research team.
(A) was (B) is (C) has (D) did
Q19の解答・解説を見る
- (A) was → 過去形の be 動詞。”Not only was the survey provide” は文法的に不成立
- (B) is → 現在形の be 動詞。”Not only is the survey provide” は文法的に不成立
- (C) has → 現在完了の助動詞。後ろに原形の provide が続く場合は did が適切
Not only did S[the revised customer satisfaction survey] V[provide] more detailed insights (into consumer preferences), but S[it] also V[introduced] a new rating system (that V[made] data analysis significantly easier (for the research team)).
Q20. The human resources department recommended hiring experienced professionals from outside the organization ------- promoting junior staff members who lacked sufficient management experience for the senior director position.
(A) instead (B) rather than (C) other than (D) as well as
Q20の解答・解説を見る
- (A) instead → “instead” 単独で than を伴う構造はない。instead of〜（前置詞 of が必要）
- (C) other than → “other than”（〜以外に）は除外を表す。選択・比較の文脈に合わない
- (D) as well as → “as well as”（〜と同様に）は追加を表す。AよりBの比較にならない
S[The human resources department] V[recommended] hiring experienced professionals (from outside the organization) rather than promoting junior staff members (who lacked sufficient management experience (for the senior director position)).
| 問題 | 正解 | パターン |
|---|---|---|
| Q1 | B | both A and B（and がシグナル） |
| Q2 | D | Not only の倒置（Not only did S V…） |
| Q3 | C | neither A nor B（nor がシグナル） |
| Q4 | A | not A but B（but がシグナル） |
| Q5 | D | both A and B → 動詞は複数（are） |
| Q6 | B | so + 形容詞 + that SV（非常に〜なので） |
| Q7 | A | either A or B（or がシグナル） |
| Q8 | C | whether A or B（どちらであろうと） |
| Q9 | D | not only A but also B（but also がシグナル） |
| Q10 | A | A rather than B（BよりむしろA） |
| Q11 | C | neither A nor B → 動詞はBに一致（複数：were） |
| Q12 | B | not only A but also B（but also でペアを完成） |
| Q13 | A | either A or B → 動詞はBに一致（複数：are） |
| Q14 | D | so + 形容詞 + that SV（such との識別） |
| Q15 | C | not A but B（but がシグナル） |
| Q16 | B | whether A or B（or がシグナル） |
| Q17 | A | not A but B（but がシグナル） |
| Q18 | C | whether A or B（どちらの条件でも） |
| Q19 | D | Not only の倒置（Not only did S V…） |
| Q20 | B | A rather than B（BよりむしろA） |
A: 5問 / B: 5問 / C: 5問 / D: 5問