- 煞费苦心 shàfèikǔxīn painstakingto take a lot of trouble; at the cost of a lot of effort or mental energy
- 苦心经营 kǔxīnjīngyíng painstakingly buildto build up or manage an enterprise through painstaking efforts
- 苦心孤诣 kǔxīngūyì painstaking effortto reach a unique level of excellence or achievement through long-term, dedicated, and meticulous work
- 皇天不负苦心人 Huángtiānbùfùkǔxīnrén perseverance rewardedHeaven will not disappoint the person who tries; if you try hard, you are bound to succeed eventually.