saber de qué pie cojea

Meanings:

• 1.

  SpainLatin Americaneutralliteral
  • Literal: to know which foot a person limps on; to be aware of the side or direction from which a limp originates.

• 2.

  SpainLatin Americaneutralcolloquial
  • Figurative: to know a person's weaknesses, biases, motives, or true intentions.