Hola, ¿cómo estás? = Hi, how are you?
Bien, ¿y tú? = Fine, and you?
Please = Por favor.
After a question or a favor you can answer:
Gracias = Thanks!
De nada = You are welcome
Es un placer = It is a pleasure
Con gusto = With pleasure, gladly
Un saludo desde Medellín, Colombia.