他每天刻苦工作。

Tā měitiān kèkǔ gōngzuò.

He works hard every day.

我把每天刻苦赚回来的钱都捐出去了。

Wǒ bǎ měitiān kèkǔ zhuàn huílái de qián dōu juān chūqù le.

I donated all the money I worked hard to earn each day.

只有通过刻苦努力，才能取得成功。

Zhǐyǒu tōngguò kèkǔ nǔlì, cáinéng qǔdé chénggōng.

Only through hard work can success be achieved.