know one's shit

present singular third person knows one's shit · participle present knowing one's shit · past knew one's shit · participle past known one's shit · alternative know the shit

1. idiomaticslangvulgarSynonym of know one's stuff, to be knowledgeable about a subject or task.

   Joe really knows his shit when it comes to plumbing.

   3 more examples

   "He really knows his shit. He knows more about guerrilla war than I could ever learn in ten lifetimes," Morales said.

   2005, Mike Tucker, Among Warriors in Iraq, →ISBN

   “Any magician can ask another magician of equal or lower level to demonstrate the test corresponding to their level or any of the levels below that,” she recited. “To prove they know their shit.”

   2011, Lev Grossman, The Magician King, →ISBN, page 134

   She knew her shit. . . . Without as much as a single stutter or misstep, she spoke about decisive point, synergistic execution, momentum shift, kinetic solution, and competent authority.

   2014, Dalton Fury, Full Assault Mode: A Delta Force Novel, →ISBN

   Synonyms: know one's stuff, to be knowledgeable about a subject or task