一旦 yídàn in case (something happens)
in case (something happens); if; once (something happens, then...); when; in a short time; in one day
How to remember 一旦: 一 one + 旦 dawn = in case (something happens).
Characters
How it is used
- Once / in the event that (something happens). 一旦决定，就不要后悔 (yídàn juédìng, jiù bú yào hòuhuǐ) once you decide, don't regret it.
- 一旦 sets up a hypothetical future condition with consequences, often paired with 就 (jiù). More formal than plain 如果 (rúguǒ).
- 一旦 (once, if ever) implies a turning point; don't confuse it with 一天 (yìtiān, a day). It's about the moment a condition is met.
Example sentences
- 坏习惯一旦被养成，便不能简单地改正。 Huàixíguàn yídàn bèi yǎngchéng, biàn bùnéng jiǎndān de gǎizhèng.Once you've formed a bad habit, you can't get rid of it easily.