How do you use "once" in a sentence?

I only met him once, at a conference in Manchester. Once you've finished, please send me the report. This area was once a thriving industrial centre.

once

Q: What does "once" mean?

One time only; as soon as; formerly Once has three main uses: indicating a single occurrence ('I've only been there once'), meaning 'as soon as' ('once you arrive'), and referring to the past ('once upon a time'). Common phrases include 'at once' (immediately), 'once again' (another time), and 'all at once' (suddenly).

Vocabulary Word BritishAmerican ★★★★★ Very Common Neutral

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Meaning: One time only; as soon as; formerly

一次，一旦，曾经

una vez, una vez que

一度、一旦、かつて

한 번, 일단 ~하면, 한때

Once has three main uses: indicating a single occurrence ('I've only been there once'), meaning 'as soon as' ('once you arrive'), and referring to the past ('once upon a time'). Common phrases include 'at once' (immediately), 'once again' (another time), and 'all at once' (suddenly).

「once」有三个主要用法：表示单次发生（「I've only been there once」）、表示「一旦」（「once you arrive」）和指过去（「once upon a time」）。常见短语包括「at once」（立即）、「once again」（再一次）和「all at once」（突然）。

«Once» tiene tres usos principales: indicar una única ocurrencia («I've only been there once»), significar «una vez que» («once you arrive») y referirse al pasado («once upon a time»). Frases comunes incluyen «at once» (inmediatamente), «once again» (otra vez) y «all at once» (de repente).

「once」には3つの主な用法があります：一度だけの発生を示す（「I've only been there once」）、「〜したら」を意味する（「once you arrive」）、過去を指す（「once upon a time」）。一般的なフレーズには「at once」（すぐに）、「once again」（もう一度）、「all at once」（突然）があります。

Once는 세 가지 주요 용법이 있습니다: 한 번의 발생('I've only been there once'), '~하자마자'('once you arrive'), 그리고 과거를 가리키는 것('once upon a time')입니다. 일반적인 표현으로는 'at once'(즉시), 'once again'(다시 한 번), 'all at once'(갑자기)가 있습니다.

Examples

I only met him once, at a conference in Manchester.
我只见过他一次，在曼彻斯特的一个会议上。
Solo lo conocí una vez, en una conferencia en Manchester.
彼には一度だけ、マンチェスターの会議で会いました。
그를 맨체스터의 한 회의에서 딱 한 번 만났습니다.
Once you've finished, please send me the report.
一旦完成，请把报告发给我。
Una vez que hayas terminado, por favor envíame el informe.
終わったら、レポートを送ってください。
끝나면 보고서를 보내 주세요.
This area was once a thriving industrial centre.
这个地区曾经是繁荣的工业中心。
Esta zona fue una vez un próspero centro industrial.
この地域はかつて繁栄した工業の中心地でした。
이 지역은 한때 번성했던 산업 중심지였습니다.

Pronunciation

Usage Guide

Context: general

Tone: neutral

Origin & History

From Middle English 'ones', genitive of 'one' — literally meaning 'of one (time)'. The 'c' spelling appeared later to indicate the /s/ sound. Similarly, 'twice' comes from 'twies' (of two times) and 'thrice' from 'thries' (of three times).

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal

Story & Trivia

The phrase 'once upon a time' has been the traditional opening for fairy tales since at least the 14th century. It creates a sense of timeless past and signals that the story is fictional.