How do you use "need to / needn't" in a sentence?

You need to sign here. She doesn't need to come. You needn't bring anything. Do I need to book in advance?

need to / needn't

Q: What does "need to / needn't" mean?

Expressing necessity or lack of necessity 'Need to' expresses necessity: 'You need to hurry.' 'Needn't' (British) or 'don't need to' shows lack of necessity: 'You needn't worry.' (= it's not necessary). Different from 'mustn't' (= prohibition).

Grammar Pattern BritishAmericanAustralian ★★★★★ Very Common Neutral

Meaning: Expressing necessity or lack of necessity

表达必要性或不必要性

Expresar necesidad o falta de necesidad

必要性または不必要性を表す

필요성 또는 불필요성 표현하기

'Need to' expresses necessity: 'You need to hurry.' 'Needn't' (British) or 'don't need to' shows lack of necessity: 'You needn't worry.' (= it's not necessary). Different from 'mustn't' (= prohibition).

'Need'可以是主要动词或情态动词。'You need to go'（主要动词）。'You needn't go'（情态动词，更正式）。'Don't need to'更常用于口语。

'Need' puede ser verbo principal o modal. 'You need to go' (verbo principal). 'You needn't go' (modal, más formal). 'Don't need to' es más común en el habla.

「Need」は本動詞または法助動詞として使えます。「You need to go」（本動詞）。「You needn't go」（法助動詞、より形式的）。「Don't need to」は話し言葉でより一般的です。

'Need to'는 필요성을 표현합니다: 'You need to hurry.' 'Needn't' (영국식) 또는 'don't need to'는 불필요성을 나타냅니다: 'You needn't worry.' (= 필요 없다). 'mustn't' (= 금지)와는 다릅니다.

Examples

You need to sign here.
你需要在这里签名。
Necesitas firmar aquí.
ここに署名する必要があります。
여기에 서명해야 합니다.
She doesn't need to come.
她不需要来。
Ella no necesita venir.
彼女は来る必要はありません。
그녀는 올 필요가 없습니다.
You needn't bring anything.
你不需要带任何东西。
No necesitas traer nada.
何も持ってこなくていいです。
아무것도 가져오지 않아도 됩니다.
Do I need to book in advance?
我需要提前预订吗？
¿Necesito reservar con anticipación?
事前に予約する必要がありますか？
미리 예약해야 하나요?

Pronunciation

Usage Guide

Context: spoken, written, everyday

Tone: directive

✓ Do Say

You need to be there by 9.
你需要在这里签名。
Necesitas firmar aquí.
ここに署名する必要があります。
9시까지 거기에 있어야 합니다.
We don't need to hurry.
她不需要来。
Ella no necesita venir.
彼女は来る必要はありません。
서두를 필요 없습니다.
You needn't apologize.
你不需要带任何东西。
No necesitas traer nada.
何も持ってこなくていいです。
사과하지 않아도 됩니다.

✗ Don't Say

You needn't to go. (no 'to' with needn't)
You needn't to go. (needn't 뒤에 'to'를 쓰지 마세요)
You mustn't worry. (mustn't = prohibition, not lack of necessity)
You mustn't worry. (mustn't = 금지이지, 불필요가 아닙니다)

Origin & History

Necessity modal

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal