无效

• Pinyin: wú xiào
• Hanzi breakdown: 无 = simplified from 無, meaning nothing/without; 效 = 交 (cross, exchange) + 攵 (tap), meaning effect or to imitate

Meaning

Invalid; ineffective; null and void. Having no effect or legal force.

Used in both everyday and legal/technical contexts. Can describe medicine that doesn't work, contracts that are void, or actions that produce no result. Opposite: 有效 (valid, effective). Common in medical, legal, and administrative language.

Examples

1. 这张优惠券已经过期，现在无效了。 This coupon has expired and is now invalid.
2. 合同因为缺少签名而被宣布无效。 The contract was declared void because it lacked a signature.
3. 吃了好几种药都无效，他决定去看中医。 After trying several medicines with no effect, he decided to see a traditional Chinese doctor.

Usage Guide

Context: legal, medical, administrative, everyday

Tone: definitive

Do Say

• 这个方法对我无效。(This method doesn't work for me.)
• 过期药品是无效的。(Expired medicine is ineffective.)

Don't Say

• 他是个无效的人 — 不能用来形容人，说'他是个无能的人'或'他没有用'

Origin & History

Compound of 无 (without, not have) + 效 (effect, effectiveness). Literally 'without effect.'

Cultural Context

Generation: All ages

Social background: Universal