勤苦

dà jiā dōu zài qín kǔ de láo zuò

大家都在勤苦地劳作。

Everyone is working diligently.

qín kǔ dú shū

勤苦读书

plod at one's books

qín kǔ liàn xí

勤苦练习

practise assiduously

dāng tā qín kǔ gōng zuò de shí hou tā méi dé dào guò gōng dao

当他勤苦工作的时候，他没得到过公道。

No justice had been shown him when he worked hard.

tā yī tiān dào wǎn zài qín kǔ gōng zuò

他一天到晚在勤苦工作。

He's plodding away day and night.