变质

• Pinyin: biàn zhì
• Hanzi breakdown: 变 = 亦 (also) + 攵 (strike); 质 = 斦 (two axes) + 贝 (shell/value)

Meaning

To deteriorate; to go bad; to degenerate (of food, quality, or character).

Literally means a change in quality, usually for the worse. Used for food spoiling, materials degrading, or metaphorically for people becoming corrupt or relationships souring. Implies an irreversible negative transformation.

Examples

1. 天气太热，牛奶放在外面半天就变质了。 The weather is too hot — the milk went bad after just half a day outside.
2. 有些官员当了几年就变质了，把初心忘得干干净净。 Some officials become corrupt after just a few years, completely forgetting their original intentions.
3. 这种材料在高温下容易变质，要注意储存条件。 This material easily deteriorates at high temperatures, so storage conditions must be watched carefully.

Usage Guide

Context: food safety, critique, storage

Tone: warning

Do Say

• 食物变质了就别吃了。(Don't eat food that's gone bad.)
• 他的思想已经变质了。(His thinking has become corrupted.)

Don't Say

• 用变质形容正常变化 (Don't use 变质 for neutral changes — it implies negative deterioration)

Origin & History

变 (change) + 质 (quality/essence). Quality changes for the worse.

Cultural Context

Generation: All ages

Social background: Universal