闲事

àn lǐ lái shuō wǒ bù yīng gāi qù guǎn zhè xián shì

按理来说，我不应该去管这闲事。

By all rights, I should just let this drop.

zài xué xiào nǐ yīng gāi shǎo guǎn xián shì

在学校，你应该少管闲事。

At school, you should mind your own business.

nǐ zěn me yǒu nà me duō xián shì

你怎么有那么多闲事？

Why do you have so many unimportant matters to do?