Guide to English grammar

72 Be going to

We use “be going to + base form” for a present situation which points to the future.
It's ten already. We're going to be late.
This fence is going to fall down soon.
We can see from the time that we are going to be late, and we can see from the condition of the fence that it is going to fall down. Be going to expresses a prediction based on these situations.

NOTE
In informal speech going to is sometimes pronounced / 'g n /.

We can also use be going to for a present intention.
I'm going to start my own business.
I'm not going to live here all my life.
They're going to build some old people's flats here.
Here the intention points to a future action. I'm going to start means that I intend to start/I have decided to start.

For a comparison of be going to and will, • 74.

NOTE

1. 
   We can use be going to without mentioning the person who has the intention.
   

The flats are going to be for old people.

2. 
   With verbs of movement, especially go and come, we often use the present continuous rather than be going to.
   

I'm going out in a minute. I've got some shopping to do.
Barbara is coming round for a chat tonight.
I'm going to go out and Barbara is going to come round are possible but less usual.


73 Present tense forms for the future

1 We use the present continuous for what someone has arranged to do.
I'm meeting Gavin at the club tonight. What are you doing tomorrow?
Julie is going to Florida.
This suggests that Julie has made arrangements such as buying her ticket.
The meaning is similar to be going to for an intention, and in many contexts we can
use either form.
We're visiting/ We're going to visitfriends at the weekend.
NOTE
a An 'arrangement' need not be with another person.