adverbial N2 common casualpolitewritten
万が一 — in the unlikely event that ~
万が一 ・ まんがいち
Meaning
- in the unlikely event that ~ / if by any chance / should the worst happen — flags a remote but serious possibility, usually something undesirable
Key sentence
万が一事故が起きたら、すぐに連絡してください。
In the unlikely event that an accident occurs, please contact us immediately.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Adverb fronting a conditional clause (たら / ば / なら / の場合) | 万が一 + [conditional clause] | 万が一失敗したら / 万が一の場合 |
When: Used for low-probability, high-stakes situations — emergencies, risks, worst cases — not everyday hypotheticals.
Examples
万が一に備えて、保険に入っておこう。
Let's get insurance just in case the worst happens.
万が一彼が来なくても、予定通り進めます。
Even in the unlikely event he doesn't come, we'll proceed as planned.
Easily confused with
Notes
- 万が一の (adnominal) modifies a noun: 万が一の事態 ('a worst-case situation'). Read まんがいち; the standalone noun 万一 'an emergency' is the same word.
See 万が一 in real sentences
Jengo shows 万が一 the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled from published Japanese grammar references.