迅速

xùnsù

adjective HSK 4 #3,990

Meanings

Both characters mean 'fast' — doubling the sense of speed.

Xiāofángyuán xùnsù gǎndào le xiànchǎng.

The firefighters quickly arrived at the scene.

Zhōngguó jīngjì xùnsù fāzhǎn.

China's economy has developed rapidly.

Qǐng xùnsù líkāi dàlóu.

Please leave the building quickly.

usage

迅速 is more formal/written than 快 (kuài). Use 迅速 in news, reports, and formal speech; use 快 in everyday conversation.

迅 xùn

速 sù