This Spanish slang phrase literally translates to 'I know the leg he/she limps with.' It means that you know someone's weakness, hidden intentions, or the truth about their character.
Examples
- Spanish: No te preocupes, sé de la pata que cojea y no me va a engañar.
- English: Don't worry, I know the leg he/she limps with and he/she won't fool me.