The 'going to'-future for prediction

The going to-future is often used, like will, to predict the future. It is common in speech, especially when we are referring to the immediate future. The speaker sees signs of something that is about to happen:

Oh, look¹ It's going to rain! Look out' She's going to faint! This use ongoing to includes the present, whereas It will ram is purely about the future. Alternatively, the speaker may have prior knowledge of something which will happen in the near future:

They're going to be married soon (Her brother told me.) A future time reference may be added with such predictions:

It's going to rain tonight They're going to be married next May We usually prefer will to the going to-future in formal writing and when there is a need for constant reference to the future as in, for example, weather forecasts.

The 'going to'-future for intentions, plans, etc.

When there is any suggestion of intentions and plans, we tend to use the going to-future rather than will in informal style:

I'm going to practise the piano for two hours this evening (i.e.

That's my intention: what I have planned/arranged to do.) However, we generally prefer will to going to when we decide to do something at the moment of speaking:

We're really lost I'll stop and ask someone the way

Intention can be emphasized with adverbs like now and just which are

generally associated with present time [compare > 7.29]: I'm now going to show you how to make spaghetti sauce I'm just going to change I'll be back in five minutes

The use of be going to to refer to the remote future is less common

and generally requires a time reference: She says she's going to be a jockey when she grows up

If we want to be precise about intentions and plans, we use verbs like intend to plan to propose to, rather than going to- They're going to build a new motorway to the west (vague) They propose to build a new motorway to the west (more precise)

The 'going to'-future in place of the present progressive

The going to-future may be used where we would equally expect to have the present progressive [> 9.11.3] with a future reference: I'm having dinner with Janet tomorrow evening I'm going to have dinner with Janet tomorrow evening