Other ways of expressing the future

However, we cannot use the present progressive to make predictions, so it would not be possible in a sentence like this: It's going to snow tonight

Though be going to can combine with go and come, the present progressive is preferred with these verbs for reasons of style. We tend to avoid going next to go or come (e.g. going to go/going to come). I'm going/coming home early this evening

9.46.4 The 'going to'-future after "if

We do not normally use will after if to make predictions [> 14.24.2], but we can use be going to to express an intention:

If you're going to join us, we'll wait for you Be going to can often be used in the main clause as well:

If you invite Jack, there's going to be trouble

Other ways of expressing the future

Forms of future substitutes

/ am/You are, etc.	to	see Mr Jones tomorrow
I am/You are, etc	due to	leave at 7 30
I am/You are, etc	about to	get a big surprise
I am/You are, etc	on the point of	leaving
I am/You are, etc	-	leaving immediately [> 9.11.3]
I/You, etc	-	leave at 7 tomorrow [> 9.8.4]

Uses of future substitutes

9.48.1 The use of 'am/is/are to'

Be to is used to refer to the future when the actions are subject to human control. Thus statements such as I'm going to faint or It's going to rain cannot be expressed with be to, which has restricted uses: e.g.

Formal arrangements/public duties: OPEC representatives are to meet in Geneva next Tuesday Compare: OPEC REPRESENTATIVES TO MEET IN GENEVA [> 9.12.5]

Formal appointments/instructions:

active: You're to deliver these flowers before 10

passive: Three tablets to be taken twice a day

Prohibitions/public notices: You're not to tell him anything about our plans (= you mustn't) POISON NOT TO BE TAKEN'

The use of 'be about to', 'be on the point of

These constructions are used to refer to the immediate future: Look¹ The race is about to start

On the point of conveys even greater immediacy: Look' They're on the point of starting'

Verbs, verb tenses, imperatives

The use of just with about to and be on the point of increases the sense of immediacy, as it does with the present progressive: They're just starting '

9.48.3 The use of 'be due to'

This is often used in connexion with timetables and itineraries: The BA 561 is due to arrive from Athens at 13 15 The BA 561 is not due till 13 15