greenmanNever mind / Let alone

Never mind and let alone are both used to emphasize that what follows is even more unlikely or difficult than what has been mentioned before.

 

E.g.

I'm too tired to walk, never mind run - No tengo fuerzas para andar, y mucho menos para correr

She can't cope with her own problems, let alone her family's - No puede con sus propios problemas, por no hablar de los de su familia

People don't understand what's going on in their own town, never mind the whole country- La gente no entiende lo que pasa en su propio pueblo, aún menos lo que pasa en todo el país