Chinese character 快

Both: 快 means “fast” in words like 快速 and contributes “happy” in 快乐. The whole word tells you which sense is active.

Early forms appear in Chu manuscripts from the Warring States period; later forms appear in seal script and Han clerical script. Shuowen, an old Chinese character dictionary, glosses 快 as joy or satisfaction and analyzes 忄 as the meaning component and 夬 as the sound component.

A historical-linguistics study published in 2025 argues that the speed sense developed after the Tang period and became dominant during the Ming and Qing dynasties. Japanese compounds preserve both branches too: 快感 means pleasure, while 快速 means high speed.

What does 快 mean in a message?

In a command, it means “hurry.” 快来 or 快点 urges someone to come or act quickly; a lone 快 sent while someone is waiting reads as urgency, not affection.

快到了 says someone or something is almost here; 快八点了 says it is almost eight. Here 快 marks an approaching event, not an order. The following verb, time expression, and 了 help make the difference.

Cantonese 快啲啦 also means “hurry up.” Cantonese pronounces 快 as faai3, unlike Mandarin kuài.

How is 快 related to 夬?

夬 supplies a sound clue, not the meaning “fast.” Traditional analysis treats 快 as 忄, the heart-related meaning component, plus 夬, the sound component. That structure fits the older sense of joy or satisfaction; sound components need not match modern pronunciation exactly.