Obligaciones en el futuro

Formación

Cuando nos referimos por escrito a obligaciones futuras, podemos emplear una construcción formal compuesta de dos elementos:
el verbo "to be" conjugado en presente conforme al sujeto + el infinitivo del verbo principal

To travel, en el sentido de obligación futura
Afirmativa Negativa Interrogativa Interrogativa negativa
I am to travel. I am not to travel. Am I to travel? Am I not to travel?
You are to travel. You are not to travel. Are you to travel? Aren't you to travel?
He is to travel. He is not to travel. Is he to travel? Isn't he to travel?
It is to travel. It is not to travel. Is it to travel? Isn't it to travel?
We are to travel. We are not to travel. Are we to travel? Aren't we to travel?
They are to travel. They are not to travel. Are they to travel? Aren't they to travel?

Funciones

En el inglés escrito podemos emplear esta construcción para expresar la obligación o exigencia de hacer algo en un momento posterior al actual. El significado es similar al de "must" pero conlleva la sugerencia de que algo se ha organizado o arreglado para que nosotros actuemos. No suele utilizarse en el inglés hablado.

Ejemplos
  • You are to leave this room at once, and you are to travel by train to London.
  • In London you are to pick up your ticket from Mr Smith, and you are to fly to your destination alone.
  • When you arrive, you are to meet our agent, Mr X, who will give you further information.
  • You are to destroy this message now.