Grammar Rule in 30 Seconds
'In the event that' is a formal substitute for 'if', used primarily in legal, professional, or emergency contexts.
- Use it for unlikely but possible future scenarios: 'In the event that it rains, the gala moves indoors.'
- Follow 'that' with a full clause (subject + verb): 'In the event that the alarm sounds...'
- Do not confuse with 'in the event of', which requires a noun: 'In the event of rain...'
Overview
if は非常に便利ですが、ビジネスの契約書、公的な通知、あるいは緊急時のマニュアルといった場面では、より精密で、かつ「あらかじめ準備された対応策」を想起させる表現が求められます。そこで登場するのが、今回学習する in the event that です。in the event that は、日本語で言えば「万が一〜という事態が発生した場合には」や「〜の際には」といった、非常にフォーマルで重みのある条件表現です。単に「もし〜なら」と可能性を提示するだけでなく、「そのような事態を想定内として、既に対応策や規定が準備されている」というニュアンスを含みます。いわば、リスクマネジメントの視点を持った言葉なのです。if と in the event that の違いに直結しています。in the event that は「従属接続詞」として機能します。つまり、この句の後に「主語 + 動詞」が続き、文全体の中で条件を表す副詞節を作ります。日本語の文法構造と比較すると、日本語では「〜という事態（event）において（in）は」という名詞句をベースにした構造に近いと言えます。if よりも客観性が高く、法的な拘束力を持たせたい文書や、厳格な手順が定められているマニュアルで多用されます。in the event that の節の中では現在形を使用します。一方で、その結果（帰結節）には、対応の義務や確実性を示すために、様々な助動詞が使い分けられます。will / shall | 確定した結果や、法的な合意事項を示す。 | In the event that the contract is terminated, all fees will be refunded. |must / should | 義務、あるいは強く推奨される行動を示す。 | In the event that you witness a security breach, you must report it immediately. |may / might | 起こりうる可能性や、裁量権があることを示す。 | The event may be postponed in the event that the weather conditions worsen. |In the event that the alarm sounds, evacuate the building at once. |in the event that を使った文を作る際は、以下のルールを厳守する必要があります。特に時制のルールは、日本語の感覚に引っ張られやすいため注意が必要です。in the event that の後に続く節の動詞は、未来の事象であっても現在形を使います。これは if 節と同様のルールですが、フォーマルな文脈ではより厳格に守られます。- 正：
In the event that the flight is cancelled, the airline will provide accommodation. - 誤：
*In the event that the flight will be cancelled...（日本語の「キャンセルされるだろう場合には」という不自然な表現に近い感覚になります）
- 1条件節が先に来るパターン
- 構成：
In the event that+ [条件節], [帰結節]. - ルール：条件節の終わりに必ずカンマを打ちます。これにより、どこまでが条件なのかが明確になります。
- 例：
In the event that the software fails to update, please contact our technical support team.
- 1帰結節が先に来るパターン
- 構成：[帰結節]
in the event that+ [条件節]. - ルール：通常、
in the event thatの前にカンマは不要です。 - 例：
The company reserves the right to cancel the agreement in the event that the payment is not received by the due date.
In the event that | In the event that... |...the server goes offline... |, が必要 | ...offline, |...the backup system will initiate automatically. |if と同じですが、使われる単語が長いため、文全体のバランスを取るためにカンマの役割が非常に重要になります。- 1契約書や法的文書 (Legal and Contractual Documents)
In the event that the tenant defaults on rent, the landlord may terminate the lease.（借主が家賃を滞納した場合には、貸主は賃貸借契約を解除できるものとする。）
- 1社内規定や公式ポリシー (Official Policies and Procedures)
In the event that an employee loses their ID badge, they must notify the HR department immediately.（従業員がIDバッジを紛失した場合には、直ちに人事部に通知しなければならない。）
- 1緊急時プロトコルと安全指示 (Emergency Protocols and Safety Instructions)
In the event that the cabin pressure drops, oxygen masks will appear from the overhead panel.（客室内の気圧が低下した場合には、頭上のパネルから酸素マスクが降りてきます。）
- 1技術仕様書や科学論文 (Technical Specifications and Scientific Writing)
The system will automatically shut down in the event that the core temperature exceeds 80 degrees.（核となる温度が80度を超えた場合には、システムは自動的にシャットダウンします。）
- 1公式なビジネスメール (Formal Business Communication)
In the event that you require further clarification, please do not hesitate to contact me.（さらなる説明が必要な場合には、遠慮なくご連絡ください。）
- 不自然：
In the event that you are hungry, let's eat ramen. - 自然：
If you're hungry, let's grab some ramen.
will の使用will を入れなきゃ」と考えてしまうミスが非常に多いです。- 間違い：
*In the event that the meeting will be postponed, we will let you know. - 正しい：
In the event that the meeting is postponed, we will let you know.
in case との混同（非常に重要！）in case= 予防・備え（何かが起きる前にアクションを起こす）in the event that= 事後対応・条件（何かが起きた後にアクションを起こす）
in case | 「〜するといけないから」（雨が降る前に傘を持つ） | I'll take an umbrella in case it rains. (雨が降るかもしれないから、今傘を持っていく) |in the event that | 「〜した場合には」（雨が降ったら試合を止める） | The match will be cancelled in the event that it rains. (実際に雨が降ったら、その時に中止にする) |in case を使うと、「問題が起きる前に〜する」という奇妙な意味になってしまうことがあります。of との使い分けミスin the event that は後ろに「節（S+V）」が来ますが、in the event of は後ろに「名詞（句）」が来ます。これを混ぜてしまうミスも散見されます。- 間違い：
*In the event of the fire starts... - 正しい：
In the event that the fire starts...またはIn the event of fire...
if | 低〜中 | 日常会話全般 | 最も一般的で汎用性が高い。 |in the event that | 高 | 契約書、公的通知 | 予期せぬ事態への公式な対応策。 |should (倒置) | 最高 | 非常に硬いビジネス文書 | Should you have any questions... のように使い、極めて丁寧。 |provided that | 高 | 契約条件 | 「〜という条件を満たすならば」という限定的なニュアンス。 |as long as | 中 | 約束、条件 | 「〜である限りは」。期間や継続性に重点。 |in the event that は、特に「ネガティブな事態や不測の事態（トラブル、遅延、事故）」に対して、組織がどう動くかを説明する際に最も適した表現です。一方で provided that は「許可を与えるための条件」など、ポジティブな文脈でもよく使われます。in the event that はメールで使っても堅苦しすぎませんか？if を使うのが無難です。in the event of と in the event that はどちらがよく使われますか？In the event of fire）では簡潔な in the event of + 名詞が好まれます。一方で、条件が「誰が何をする」のように少し複雑になる場合は、in the event that + 節の方が正確に情報を伝えられます。if を in the event that に置き換えるだけで丁寧になりますか？In the event that you are late, I'll be mad. と言うと、文の前半は非常に硬いのに、後半（I'll be mad）が非常にカジュアルで、ちぐはぐな印象を与えます。後半も disciplinary action may be taken（懲戒処分が下される可能性がある）のように、フォーマルな語彙で統一することが大切です。in the event that の方が「予期せぬ出来事」や「重大な事象」というニュアンスが強いです。単なる「お帰りの際は」のような日常的な動作には、when や as you leave を使うのが一般的です。Structure of 'In the event that'
| Conjunction | Subject | Verb (Present Simple) | Result Clause |
|---|---|---|---|
|
In the event that
|
the alarm
|
sounds
|
exit the building.
|
|
In the event that
|
it
|
rains
|
the game is cancelled.
|
|
In the event that
|
you
|
lose
|
your key, call me.
|
|
In the event that
|
he
|
does not pay
|
he must leave.
|
|
In the event that
|
the CEO
|
should resign
|
we will vote.
|
Meanings
A complex conjunction used to introduce a condition that might happen in the future, typically implying a prepared response or a formal consequence.
Legal/Contractual Contingency
Specifying what happens if a contract is breached or a specific legal condition is met.
“In the event that the tenant fails to pay rent, the lease shall be terminated.”
“In the event that the goods are damaged, the seller will provide a full refund.”
Emergency Procedures
Instructions for what to do during rare but serious incidents.
“In the event that the cabin pressure drops, oxygen masks will fall from the ceiling.”
“In the event that you hear a fire alarm, please exit the building via the stairs.”
Professional Planning
Discussing business 'Plan B' scenarios in meetings or emails.
“In the event that the shipment is delayed, we should notify the client by noon.”
“In the event that we exceed our budget, we will need to cut marketing costs.”
Reference Table
| 構造 | 意味 | フォーマル度 | 例文 |
|---|---|---|---|
|
In the event that + S + V(present)
|
特定の状況が発生した場合
|
フォーマル
|
`In the event that` the system fails, restart it.
|
|
S + will/may/should + V + in the event that + S + V(present)
|
状況が発生した場合にアクションが起こる
|
フォーマル
|
You `will be refunded in the event that` your flight is cancelled.
|
|
If + S + V(present)
|
通常の条件
|
インフォーマル/中立
|
`If` it rains, we'll stay inside.
|
フォーマル度スペクトル
In the event that a fire breaks out, please exit via the nearest stairwell. (Safety instruction)
If there is a fire, please use the stairs to leave. (Safety instruction)
If it catches fire, get out fast! (Safety instruction)
If it's blazing, bail! (Safety instruction)
In The Event That：主要な概念
意味
- If (formal) フォーマルな「もしも」
- Should it occur 不測の事態
- When/if (serious) 重大な条件
使用法
- Contracts 法的文書
- Emergency plans 緊急計画
- Formal instructions 公式指示
構造
- In the event that + S + V(present) 節の構造
- Main clause (future) 主節（未来）
対比
- `If` (casual) 日常の条件
- `In case` (precaution) 似ているが微妙に異なる
In The Event That vs. If vs. In Case
「In The Event That」を使うべき？
文脈はフォーマルですか（例：方針、契約、公式な連絡）？
発生した場合に明確な行動が必要となる、正確な条件を指定していますか？
「In The Event That」が活躍する場面
法律・公式
- • 契約書
- • 会社の方針
- • 利用規約
緊急計画
- • 避難手順
- • 災害プロトコル
- • 緊急時対応計画
ビジネス・管理
- • フォーマルなメール
- • プロジェクト憲章
- • サービス契約
技術マニュアル
- • トラブルシューティングガイド
- • システムフェイルセーフノート
- • ユーザーマニュアル
レベル別の例文
In the event that you are late, call me.
If you are late, call me.
In the event that it is cold, wear a coat.
If it is cold, wear a coat.
In the event that you need help, ask a teacher.
If you need help, ask a teacher.
In the event that the bus is full, wait for the next one.
If the bus is full, wait.
In the event that the hotel is full, we will find another room.
If the hotel is full, we'll find another.
In the event that you do not have a ticket, you cannot enter.
If you don't have a ticket, you can't enter.
In the event that the rain stops, we can play tennis.
If the rain stops, we can play.
In the event that the computer breaks, call the office.
If the computer breaks, call the office.
In the event that the meeting is cancelled, I will send an email.
If the meeting is cancelled, I'll email.
In the event that you lose your passport, contact the embassy.
If you lose your passport, call the embassy.
In the event that the product is faulty, you can return it.
If the product is broken, you can return it.
In the event that no one answers, please leave a message.
If no one answers, leave a message.
In the event that the candidate fails to appear, the interview will be rescheduled.
If the candidate doesn't show up, we'll reschedule.
In the event that the software requires an update, the system will notify you.
If the software needs an update, you'll be notified.
In the event that the company goes bankrupt, the assets will be sold.
If the company fails, assets are sold.
In the event that the alarm is triggered, security will arrive in five minutes.
If the alarm goes off, security comes.
In the event that the primary server should fail, the secondary server takes over.
If the main server fails, the backup starts.
In the event that the terms are not met, the contract is null and void.
If terms aren't met, the contract is dead.
In the event that the witness refuses to testify, the prosecution may struggle.
If the witness won't talk, the case is hard.
In the event that the currency fluctuates wildly, we will hedge our investments.
If the money changes value, we'll protect ourselves.
In the event that the geopolitical climate deteriorates, we must reassess our supply chain.
If politics get worse, we change our supply.
In the event that the findings are deemed inconclusive, further funding will be withheld.
If results are unclear, no more money.
In the event that the monarch is unable to perform their duties, a regent is appointed.
If the King/Queen can't work, a regent takes over.
In the event that the merger should be blocked by regulators, the stock price will plummet.
If the merger is stopped, stocks will fall.
間違えやすい
Learners use 'that' with nouns or 'of' with clauses.
Both are formal, but inversion is even more formal and omits 'if' or 'in the event that'.
'In case' is used for precautions (doing something *before*), whereas 'in the event that' is for reactions (doing something *after*).
よくある間違い
In the event that rain, stay inside.
In the event that it rains, stay inside.
In the event of it rains...
In the event that it rains...
In the event that you will be late...
In the event that you are late...
In the event that you hungry...
In the event that you are hungry...
In the event that the bus don't come...
In the event that the bus doesn't come...
In the event that fire...
In the event of fire...
In the event that you are needing help...
In the event that you need help...
In the event that the meeting would be cancelled...
In the event that the meeting is cancelled...
In the event that you forgot your password...
In the event that you forget your password...
In the event that it may rain...
In the event that it rains...
In the event that the company should to fail...
In the event that the company should fail...
文型パターン
In the event that ___, please ___.
What should I do in the event that ___?
In the event that the ___ should ___, we will ___.
The contract states that in the event that ___, the ___ is ___.
Real World Usage
In the event that the cabin loses pressure, masks will drop.
In the event that the buyer defaults, the deposit is forfeited.
In the event that I am out of the office, please contact Sarah.
In the event that you hear the alarm, do not use the elevator.
In the event that you violate these terms, your account may be banned.
In the event that the train is delayed, we apologize for the inconvenience.
「準備」を意識しよう
節の中に「will」は使わないで！
飾りではなく、明確さのために使おう
文脈がすべて！
カンマの位置
Smart Tips
Swap 'if' for 'in the event that' to sound more professional and prepared.
Change 'of' to 'that' to make the grammar correct.
Add the word 'should' after the subject.
Use 'In the event of' for short signs and 'In the event that' for detailed manuals.
発音
The 'that' reduction
In natural speech, 'that' is often reduced to a schwa sound /ðət/.
Stress pattern
The primary stress is on the second syllable of 'event'.
Rising-Falling
In the event that it rains (rising), we'll stay home (falling).
The condition has a rising pitch to show it's not finished, the result falls.
暗記しよう
記憶術
Remember the 'T' in 'That' stands for 'Total sentence' (Subject + Verb).
視覚的連想
Imagine a thick, dusty legal book. On the first page, in big gold letters, it says 'IN THE EVENT THAT'. This helps you associate the phrase with formal, official rules.
Rhyme
In the event that things go wrong, the formal 'if' will make you strong.
Story
A lawyer is preparing for a storm. He doesn't say 'If it rains.' He says, 'In the event that precipitation occurs, we shall deploy the umbrellas.' He is ready for any contingency.
Word Web
チャレンジ
Write three emergency instructions for your office or home using 'In the event that'.
文化メモ
Very common in formal British public announcements (e.g., on the Tube or at train stations). It reflects a cultural preference for formal politeness in official settings.
Standard in 'Legalese'. Americans use this to make contracts sound ironclad and professional.
Used globally in English-speaking offices to sound objective and less personal than 'if'.
Derived from the Latin 'eventus' (occurrence/outcome). The phrase 'in the event' appeared in English in the 1600s.
会話のきっかけ
In the event that you won the lottery tomorrow, what would be your first purchase?
In the event that your flight is delayed for 10 hours, how do you spend the time?
In the event that you were offered a job in a different country, would you take it?
What should a citizen do in the event that they witness a crime?
日記のテーマ
よくある間違い
Test Yourself
In the event that the projector ___ down, we have a backup presentation ready.
Find and fix the mistake:
In the event that you will be late, please inform us by phone.
Translate into English: 'En caso de que la alarma suene, evacuen el edificio.'
Answer starts with: ["I...
Choose the correct sentence:
Score: /4
練習問題
8 exercisesIn the event ___ the power goes out, use the flashlight.
In the event ___ a fire, do not use the elevators.
Find and fix the mistake:
In the event that it will rain, the concert is cancelled.
If the shipment is delayed, we will call you.
'In the event that' is more formal than 'if'.
Manager: 'What is our plan ___ the client rejects the proposal?'
Select the correct option.
event / that / in / the / fails / system / the / restart / it
Score: /8
Practice Bank
12 exercisesThe company policy states that `in the event that` an employee ___ company property, disciplinary action will be taken.
We will provide a full refund in the event of that you are not satisfied.
Translate into English: 'Si el servidor principal falla, se activará el sistema de respaldo.'
Which statement correctly uses the formal conditional?
Arrange these words into a sentence:
Match the conditional phrases with their appropriate outcomes:
`In the event that` the conference ___ rescheduled, all registered participants will be notified.
If you need anything, just call me, in the event that.
Translate into English: 'Si hubiera un problema con la entrega, por favor, avísenos de inmediato.'
Which sentence would be most suitable for a company policy?
Arrange these words into a sentence:
Match the beginning of the sentence with its logical ending:
Score: /12
よくある質問 (8)
Technically yes, but it would sound very strange and sarcastic. Stick to `if` for texting.
No. `In case` is for preparation (I'll take a coat in case it rains). `In the event that` is for a reaction (In the event that it rains, we will go inside).
Yes, if the 'in the event that' clause comes first, use a comma before the main clause. Example: `In the event that it rains, we will cancel.`
No, just like with `if`, you should use the present simple to talk about the future. Say `In the event that he arrives`, not `In the event that he will arrive`.
`In the event of` is shorter and used with nouns (In the event of fire). It's very common on signs where space is limited.
Yes, it is very common in American legal documents and formal business settings.
Adding `should` (In the event that it should rain) makes the event sound even less likely and more formal.
Yes, it is perfectly appropriate for academic writing when discussing hypothetical conditions or results.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
En caso de que
Spanish uses the subjunctive; English uses the present simple.
Au cas où
French uses the conditional mood; English uses present simple.
Im Falle, dass
Very similar in usage and register.
万が一 (Man'gaichi)
Japanese emphasizes the extreme unlikelihood more than the English phrase.
في حال (Fi hal)
Arabic can use it with both nouns and clauses more flexibly.
万一 (Wànyī)
Chinese 'Wànyī' is often used for bad things, while English can be neutral.
Learning Path
Prerequisites
Learn These First
関連動画
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