迅速

xùnsù

adjective HSK 4 #3,990

Meanings

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

消防员迅速赶到了现场。

Xiāofángyuán xùnsù gǎndào le xiànchǎng.

The firefighters quickly arrived at the scene.

中国经济迅速发展。

Zhōngguó jīngjì xùnsù fāzhǎn.

China's economy has developed rapidly.

请迅速离开大楼。

Qǐng xùnsù líkāi dàlóu.

Please leave the building quickly.

usage

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

迅 xùn

速 sù