无效

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

含义

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.

例句

1. 这张优惠券已经过期，现在无效了。
2. 合同因为缺少签名而被宣布无效。
3. 吃了好几种药都无效，他决定去看中医。

用法指南

语境: legal, medical, administrative, everyday

语气: definitive

正确说法

• 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.)

错误说法

• 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'

起源与历史

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

文化背景

世代: All ages

社会背景: Universal