用 心

motive
intention
to be diligent or attentive
careful

例句

要用心，不要操心、烦心。

yào yòng xīn, bù yào cāo xīn, fán xīn.

Be diligent, don't worry or be annoyed.

学生们用心学习了很多首诗。

xué sheng men yòng xīn xué xí le hěn duō shǒu shī.

The students learned many poems by heart.

出现在

别有用心bié yǒu yòng xīnto have an ulterior motive (idiom)良苦用心liáng kǔ yòng xīnto ponder earnestly 无所用心wú suǒ yòng xīnnot paying attention to anything (idiom); to idle time away 用心良苦yòng xīn liáng kǔto ponder earnestly 饱食终日，无所用心bǎo shí zhōng rì , wú suǒ yòng xīnto eat three square meals a day and do no work (idiom)