万一 (wànyī) means "in case" or "what if" in Mandarin, and it's used specifically for low-probability, usually negative situations. Unlike 如果 (rúguǒ), which covers any conditional, 万一 signals that the event probably won't happen — but you want to be prepared if it does.
The structure is straightforward: put 万一 before an unlikely and usually bad event, then follow with 就 (jiù) and your backup plan. The key sentence for this lesson is:
万一航班取消了，我们就改签下一班。 (wàn yī háng bān qǔ xiāo le, wǒ men jiù gǎi qiān xià yì bān.) — "In case the flight gets canceled, we'll rebook the next one."
You can also use it to ask "what if" questions: 万一下雨怎么办？ (wànyī xiàyǔ zěnme bàn?) — "What if it rains?" — or to suggest precautions: 带把伞吧，万一下雨 (dài bǎ sǎn ba, wànyī xiàyǔ) — "Bring an umbrella in case it rains."
This is a live conversation lesson — you talk out loud with AI teacher Mei Lin in real time, not by typing. Each lesson targets one grammar pattern and takes roughly 10 minutes. Mei Lin corrects your grammar and pronunciation in the flow of conversation and adapts to your level. In "Preparing for the Worst," you'll practice warning someone about unlikely problems, suggesting precautions for worst-case scenarios, and asking "what if" questions about things that probably won't happen but could.
After this lesson, explore more HSK 5 lessons, or try another HSK 5 live lesson on shifting topics with 至于 (zhìyú) and another on 不得已 (bùdéyǐ) for last-resort situations. You can also print practice sheets with the free Chinese worksheet generator. Your first lesson is free to start.
万一 (wànyī) is only for low-probability, usually negative situations — things that probably won't happen but could. 如果 (rúguǒ) is a general conditional covering any "if" scenario. Use 万一 when you're warning someone or planning for a worst-case scenario, like a flight cancellation, not for ordinary conditions.
Use the pattern 万一 + Unlikely Event，就 + Response. For example, 万一航班取消了，我们就改签下一班 (wàn yī háng bān qǔ xiāo le, wǒ men jiù gǎi qiān xià yì bān) means "In case the flight gets canceled, we'll rebook the next one." The 就 introduces your backup plan or precaution.
Yes. Add 怎么办 (zěnme bàn) after 万一 and an unlikely event to ask "what if" — for example, 万一下雨怎么办？ (wànyī xiàyǔ zěnme bàn?) means "What if it rains?" This is one of the speaking skills you practice in the "Preparing for the Worst" live lesson with Mei Lin.
This live conversation lesson takes roughly 10 minutes and focuses on the single grammar pattern 万一 (wànyī) — In Case / What If (Low Probability). You talk out loud with AI teacher Mei Lin, who corrects your grammar and pronunciation as you practice warning about unlikely problems and suggesting precautions.