知しるものか

expression

who cares?; see if I care; who knows?; how should I know?

Emphatic dismissive expression: the speaker strongly denies caring or knowing. Often used in casual, sometimes confrontational speech. The ものか ending adds a rhetorical, defiant tone.

• あいつのことなんか知しるものか。

  Who cares about that guy? / See if I care about him.

• そんなこと、知しるものか。