affair; matter; thing; business; CL:件[jian4],樁|桩[zhuang1]

it's not important; it's nothing; never mind; to have nothing to do; to be free; to be all right (out of danger or trouble)

old practice

narrative; story; tale

what's the matter?; what's going on?; how could that be?; how did that come about?; what's it all about?