know one's shit

Definitions

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

idiomatic, slang, vulgar

Examples

“Joe really knows his shit when it comes to plumbing.”

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

““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.””

“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.”

CEFR level