HSK 5

一旦 (yí dàn) — how to say "once" in Chinese

一旦

Once, if, in case

linking adverb

How to use it

Goes after the subject, before the verb — not at the start like a conjunction.

你一旦开始,就别停。

nǐ yí dàn kāi shǐ jiù bié tíng

Once you start, don't stop.

Rule: Expressing "once…then…" with "一旦 (yídàn) … 就 (jiù) …" →

Character composition

一

one

旦

dawn, day

Radicals / Keys

日

Sun

#72 · rì · 4 strokes

一

One

#1 · yī · 1 stroke

Synonyms

Collocations

一旦发生

yí dàn fā shēng

once it happens

一旦失去

yí dàn shī qù

once lost

Examples

一旦你开始学习汉语,就会发现它很有趣。

Once you start learning Chinese, you'll find it very interesting.

一旦下雨,就不去。

If it rains, we won't go.

Writing

Frequently asked questions

How do you say "once" in Chinese?

"once" in Chinese is 一旦 (yí dàn).

一旦 meaning in English

一旦 (yí dàn) means "Once, if, in case".

How is 一旦 pronounced?

It is pronounced yí dàn (written as yi dan, yidan). You can listen to the pronunciation on this page.

How do you write "once" in Chinese characters?

It is written 一旦: 一 has 1 stroke, 旦 has 5 strokes. The Writing section above animates the stroke order of each character and lets you trace it.

What HSK level is 一旦?

一旦 belongs to the HSK 5 vocabulary list.

Tomyo

Learn Chinese words with spaced repetition

Add 一旦 to your vocabulary and remember it with smart reviews, audio and examples.

Download the app

Grammar with 一旦

More HSK 5 words