🧵 文法ジャンル別の解き方
TOEIC Part5「接続詞」の解き方と頻出パターン｜練習10問つき
接続詞の問題は「空所の後ろに主語＋動詞があるか」の確認から始めます。文と文をつなぐなら接続詞、名詞だけなら前置詞です。そのうえで、2つの文の関係（理由・譲歩・条件・時）に合う接続詞を選びます。
解き方のポイント
- 後ろが文なら接続詞、名詞なら前置詞（although ⇔ despite、because ⇔ because of）
- 理由：because / since / as、譲歩：although / even though、条件：if / unless / provided that
- 時：when / while / before / after / once / as soon as
- unless は「〜しない限り」= if 〜 not
- once は接続詞として「いったん〜すると」の意味で頻出
ひっかけ注意
- however は副詞なので2つの文を直接つなげない（カンマとセミコロンで使う）
- even though と even if：前者は事実、後者は仮定
- so that（〜するために）と so（だから）の区別
例文で確認
| Although the price was high, the product sold well. | 後ろが文で「〜だけれども」→ Although |
| Your order will ship once payment is confirmed. | 「いったん〜すれば」→ once |
| Do not open the file unless you have permission. | 「〜しない限り」→ unless |
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. ___ the merger is finalized, the two companies will operate independently.
答えと解説を見る
正解: A) Until
The meaning is 'the two companies will operate independently until the merger is finalized' — marking the endpoint in time. The conjunction 'Until' is correct. 'Since' marks a starting point, the opposite meaning. 'While' expresses simultaneity but doesn't convey the sense of a cutoff at completion of the merger. 'Unless' means 'except if', a condition rather than a time boundary.
Q2. The company has grown rapidly, ___ it now employs over five hundred people.
答えと解説を見る
正解: A) and
'Grown rapidly, and as a result now employs over 500 people' — the two halves point in the same direction, so the additive 'and' is correct. 'But' is contrastive and doesn't fit content moving in the same direction. 'Or' expresses alternatives, and 'nor' pairs negative items — neither fits the meaning here.
Q3. The conference has been postponed ___ the severe weather conditions.
答えと解説を見る
正解: C) because of
What follows is 'the severe weather conditions', a noun phrase. Only 'because of' (a compound preposition) can introduce a noun phrase here. 'Because' is a conjunction and needs a clause (subject + verb) after it, which isn't available. 'Although' and 'so that' are also conjunctions that require a clause.
Q4. Our production costs have decreased ___ we adopted the new process.
答えと解説を見る
正解: A) since
What follows the blank is the clause 'we adopted the new process'. Among conjunctions that take a clause, 'since' (meaning 'because'/'ever since') fits the meaning — it can also be read as a starting point in time. 'For' can act as a coordinating conjunction expressing reason, but it normally needs a comma before it, which is awkward here. 'During' and 'despite' are prepositions and can't take a clause.
Q5. We cannot process your order ___ payment has been received.
答えと解説を見る
正解: A) until
The meaning is 'we cannot process orders until payment is confirmed'. 'Not ... until' is a set pairing meaning 'not until X happens', so 'until' is correct. 'While' means simultaneous duration. 'During' is a preposition and can't take a clause. 'Because' would reverse the logic, implying orders can't be processed because payment was confirmed.
Q6. The department director will announce the results ___ the meeting ends.
答えと解説を見る
正解: A) as soon as
What follows is 'the meeting ends' — a full clause (subject + verb). A conjunction is needed, and 'as soon as' also fits the meaning best. 'In case of' and 'instead of' are compound prepositions that take a noun phrase, not a clause. 'Such as' means 'for example' and doesn't fit the meaning of immediate sequence.
Q7. Please ensure that all invoices are approved ___ they are processed.
答えと解説を見る
正解: A) before
The meaning is 'make sure invoices are approved before they are processed' — a time sequence. The conjunction 'before' fits. 'During' is a preposition and can't introduce a clause. 'Despite' is also a preposition. 'Unless' means 'except if' and doesn't express the order of approval then processing.
Q8. The instructions specify ___ the machine should be cleaned after each use.
答えと解説を見る
正解: A) that
What follows the blank is 'the machine should be cleaned after each use' — a complete clause with nothing missing. The conjunction 'that' introduces a complete clause as the object of a verb. 'What' is a relative pronoun and needs an incomplete clause after it (missing a subject or object). 'Which' and 'whose' also need something missing after them. The test is whether what follows is complete or incomplete.
Q9. Ms. Romero has been with the firm ___ she graduated from university.
答えと解説を見る
正解: B) since
What follows the blank is the clause 'she graduated from university', expressing 'ever since graduating'. The conjunction 'since' is correct, and it pairs naturally with the present perfect 'has been'. 'For' marks a length of time and doesn't take a clause. 'During' is a preposition. 'While' means 'during the time that' (simultaneity) and doesn't mark a starting point.
Q10. The technician will call you ___ he has diagnosed the problem.
答えと解説を見る
正解: A) once
What follows is the clause 'he has diagnosed the problem'. The conjunction 'once' (meaning 'as soon as') fits the meaning. 'During' and 'in spite of' are prepositions and can't take a clause. 'Whether' means 'whether or not' and doesn't match the meaning of when contact will happen.