刻苦

tā suī rán bù shì hěn cōng ming dàn hěn kè kǔ

她虽然不是很聪明，但很刻苦。

She is not very clever but she is painstaking.

jiào liàn ràng duì yuán men kè kǔ liàn xí kòng qiú

教练让队员们刻苦练习控球。

The coach made the team work hard on ball control.

tā xué xí jí qí kè kǔ

他学习极其刻苦。

He is remarkably assiduous at his study.

guò zhe kè kǔ de shēng huó

过着刻苦的生活

lead a simple and frugal life