"Going to" to talk about the future in English

We use the future with going to when we know with certainty what will happen. And, following this same logic, when we talk about something we have already decided to do:

Voy a morir algún día.	I’m going to die one day.
Esta noche voy a ver una película.	I’m going to watch a film tonight.

First we will see the affirmative structure. It is as simple as following the order: subject, verb to be, going to and verb in infinitive.

Voy a decir adiós.	I’m going to say goodbye.
(Él) Va a contar una historia.	He’s going to tell a story.

For the negative structure, we simply place not after the verb to be:

No voy a coger el teléfono.	I’m not going to pick up the phone.
No vamos a coger ese vuelo.	We aren’t going to catch that flight.

In the questions we exchange the verb to be with the subject, and the rest remains the same:

¿Vas a beberte la leche?	Are you going to drink your milk?
¿Va a sentarse aquí? (Ud.)	Are you going to sit here?