在乎

to care about / equivalent of 在於|在于[zai4 yu2]

to exist; to be alive / (of sb or sth) to be (located) at / (used before a verb to indicate an action in progress)

(classical particle similar to 於|于[yu2]) in / at / from / because / than / (classical final particle similar to 嗎|吗[ma5], 吧[ba5], 呢[ne5], expressing question, doubt or astonishment)

not to care

not in the least concerned (idiom) / reckless / couldn't give a damn about it / unperturbed / couldn't care less / harum scarum

really does not care