Will or be going to

Compare will and be going to:

1. We use will with an infinitive (do, go, be arrive, etc.):

INFINITIVE

John will arrive tomorrow.


2. We use will for actions that we decide to do Now, at the moment of speakking:


past ---------------------------> now
speaking
decision


I like this coat. I think I'll buy it.

A: What would you like to eat?
B: I'll have a pizza , please.

We can use will for offers and promises:

I'll carry your case for you. (OFFER)
I won't forget your birthday again (PROMISE)


3. We use will to talk about things that we think or believe will happen in the future:

I'm sure you'll enjoy the film.
I'm sure it won't rain tomorrow. It'll be another beautiful, sunny day.


We use be going with to + infinitive ( to do, to be, to rain, etc.):

to + INFINITIVE

It's going to rain soon.
My friends are going to come tonight.
It isn't going to rain today.
What are you going to do on Sunday?

We use be going to for actions that we have decided to do BEFORE we speak:

past ---------------------------------> now
decision speaking

I'm going to clean my room this afternoon.
( I decided to clean it this morning.)

We can ask questions about people's plans:

Are you going to take the three o'clock train?
(=Have you decided to take the three o'clock train?)

We use be going to for something that we expect to happen, because the situation now indicates that it is going to happen:

He's running towards the goal, and he's going to score.