- 开开心心 kāikāixīnxīn happilyin a state of being very happy, cheerful, or joyful; usually used as an adverbial modifier to describe an action.
- 寻开心 xúnkāixīn seek diversionto enjoy oneself or look for pleasure and amusement
- 开心果 kāixīnguǒ jolly personan amusing person who brings joy to others
- 开心颜 kāixīnyán smilinga happy or smiling countenance or expression
- 敞开心扉 chǎngkāixīnfēi open one's heartto be honest and reveal one's true thoughts or feelings to someone else; to open up emotionally.