HSK 4 grammar · conjunction
万一…就
万一 — in case / if by any chance
Pattern
+ +
( ) can be left out · other words may come before, between and after
How it works
万一 introduces an unlikely but worrying possibility — "in case", "if by any chance". It marks a small-chance, usually undesirable event, and the main clause says what to do if it happens.
Examples
万一下雨，我们就改天去。
Wànyī xià yǔ, wǒmen jiù gǎitiān qù.
In case it rains, we'll go another day.
多带点钱，万一不够呢。
Duō dài diǎn qián, wànyī bú gòu ne.
Bring extra money, in case it's not enough.
万一他不同意，你有别的办法吗？
Wànyī tā bù tóngyì, nǐ yǒu bié de bànfǎ ma?
If by chance he disagrees, do you have another plan?
Related
See it in a story
In the app, 万一…就 is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.