To Politely Accept: "Sí, gracias."

-"¡Sí, gracias!"

This tiny little expression is confusing to English-speakers because it's the equivalent of "Yes, please." If your first language is English, your instinct will be to use a direct translation (which would be understood--phew!).

Over winter break, practice this expression in a Mexican restaurant:

-More chips?
-¡Sí, gracias!

-¿Otra margarita?
¡Sí, gracias!

Then when you back in class or in the office, use it in those contexts:

-¿Te entrego la tarea?
-¡Sí, gracias!

-¿Te cierro la puerta?
-¡Sí, gracias!