BE GOING TO indicates a plan, and the Present Continuous an arrangement.
One, and only one, way of expressing the future is ‘correct’ in any particular context.
As we shall see in the next few pages, the reality of how to express futurity is made much less problematic if we understand the reality:
* There is no Future Tense in English. WILL is one of the modals, all of which can express futurity:
* BE GOING TO does not indicate a plan. It is hard to imagine who or what might be planning anything in such utterances as:
Look at those clouds. It’s going to rain.
George is a terrible driver. He’s going to have an accident one day.
* There is often more than one possible correct way to express futurity. For example in this utterance:
Emma … (fly)… to London next week,
if we have no further contextual evidence, we can ‘fill the gap’ with any or all of the following: flies/is flying/is going to fly/will fly/will be flying/will have flown/is to fly, not to mention such possibilities as: wants/hopes/expects/etc to fly.
1. A Future Tense in English?
If we mean by the word tense ‘inflected term’,then it should be clear that there are only two such forms in English, the Present Simple and the Past Simple. Such forms as theProgressive (or Continuous) and Perfect, formed with an auxiliary are more usefully considered as aspects; and futurity is more usefully considered with such concepts as certainty and intention. There is no Future Tense as such in English, simply a number of ways in which we can speak about future situations. In the following sections, we shall consider the most important of these ways.
2. BE (do)ING and BE GOING TO (do)
2.1. The Present Progressive (/Present Continuous)
A better name for this aspect might be durative, as it is used whenhe speaker wishes to indicate that the situation spoken of has duration, and that that duration is limited, i.e. it has a beginning and end. Precisely when the beginning and end are may not be important, but the fact that they are there, and are not considered remote in time are important. Consider these three utterances:
The number 22 tram is running through Flora this week.
I am meeting my wife at the pub this evening.
In , the limited duration of the writing is clearly understood from the context, (as is, incidentally, the fact that the action is going on at the moment of speaking).
In , the known context of the normal route of the 22 tram (which does not pass through Flora) confirms the limited duration of he situation. Incidentally, it is perfectly correct for this to be said at 3 a.m., when no number 22 tram is actually running.
I, the speaker, can say  because I know that my wife and I arranged the meeting this morning. The arrangement to meet has limited duration – it began this morning and ends when we actually meet. Considered this way, it can be useful to think of the Progressive form as indicating an arrangement.
If an arrangement of limited duration is what the speaker has in mind, then the example given in the introduction will be realized as:
Emma is flying to London next week.
2.2. BE GOING TO
Forms with BE GOING TO possibly originated in such utterances as:
We are going to meet George at the stadium,
uttered when we were literally going, i.e. on the way, to the meeting. At the moment of speaking there was present evidence of the future meeting. This use has become extended to embrace any action for which there is present evidence – things do not have to be literally moving. Consider now these two utterances:
Look at those black clouds. It’s going tosnow.
Pat is going to fly to Phuket next week.
In  the present evidence is clear – the black clouds. In , the present evidence may be the flight ticket that Pat has just shown the speaker, or it may simply be the knowledge in the speaker’s mind that s/he has somehow acquired. This explains why, when the grammatical subject of the verb is capable of planning, there may be little practicaldifference between the use of the ‘Progressive’ form and the BE GOING TO form. However, with a grammatical subject incapable of planning, there is a difference:
3.I am meeting my wife at the pub this evening.
3a. I am going to meet my wife at the pub this evening.
7. It’sgoing to snow.
7a. It’s snowing.
7b. *It’s snowing tomorrow.
In  the speaker has made the arrangement. In [3a] the speaker may have made the arrangement (the present evidence), he/she may just have been informed by his wife (the present evidence), or may have recently made a plan (the present evidence). The circumstances surrounding the situations in  and [3a] differ, but the practical result is the same; the speaker has free choice between the two forms. Neither is ‘better, ‘more appropriate’ or ‘more correct’.
In , the present evidence is something like the presence of black clouds, or the speaker’s knowledge of the weather forecast. In [7a], it is impossible for an arrangement to be made for future snow, and therefore the Progressive form used here cannot be referring to future arrangement. The context will therefore inform us that snow is actually falling as the utterance is made. The addition of a time-indicator cannot make the impossible possible, and [7b] is therefore not a possible utterance.
We have seen above that if an arrangement of limited duration is what the speaker has in mind, then the example given in the introduction will be realised as:
Emma is flying to London next week.
We can now say that if the speaker has present evidence of next week’s flight, then the example will be realized as
Emma is going to fly to London next week.
The preceding paragraphs help to explain why, in gap-fill exercises, students sometimes come up with a ‘wrong’ answer, i.e. a different one from that expected by the teacher or compiler of the exercise. In real life, the speaker is trying to say what s/he wants to say; in gap-fill exercises, the student is trying to guess what the compiler would have said in a context that is not made sufficiently clear.
In the following sections we shall consider the implications of other ways of expressing the future. We should clearly remember, however, that what you or I might wish to say in a particular situation may well be different from what somebody else might wish to say. In the situation of Emma flying to London, we have already seen two possible ‘correct’ utterances. There will be more to come – the range is almost endless. As the actual context becomes more explicit, this range may become narrower, but we should not assume that there is always only one ‘correct’ utterance or that certain utterances are inevitably impossible.
3. Present Simple
In English, as in many Indo-European languages, the so-called ‘Present’ tense functions more like a default tense; it is used when there is no need for any additional temporal or aspectual information carried by other forms. The time of the situation denoted by the present simple tense of the verb can be past , present , ‘general’  or future :
8. Jane tells me you’ve not been too well since you got back.
9. My stomach hurts.
10. I never drink alone.
11. The UN General Assembly opens in New York late this month.
Thus, in our example of Emma’s flight, if we imagine the speaker mentally seeing Emma’s schedule and presenting a neutral fact, without any of the overtones suggested by other ways of expressing the future the realization will be:
Emma flies to London next week.
The futurity is shown by the context or by explicit time-markers.
WILL is a modal and, like the other modals, has two core meanings. The two modal meanings are
(a) the ‘extrinsic’ meaning, referring to the probability of the event/state
(b) the ‘intrinsic’ meaning, reflectingsuch concepts as: ability, necessity,
obligation, necessity, permission, possibility, volition, etc.
The extrinsic meaning of WILL is exemplified in:
12. Luke left three hours ago, so he will be in London by now.
13. There will be hotels on the moon within the next 50 years.
14. T he afternoon will be bright and sunny, though there may be rain in the north.
In all three examples, the speaker suggests 100% probability, i.e. absolute certainty. (MAY would imply possibility, MUST logical certainty, to take examples of two other modals). Note that while certainty in  and  is about the future, in  it is about the present. It is the absolute certainty, in the minds of speaker/writer and listener/reader, that can give the impression that forms using ‘the WILL future’ are some way of presenting ‘the future as fact’. Some writers therefore call this form ‘the Future Simple’. Weather forecasters, writers of business/scientific reports, deliverers of presentations, etc, frequently use WILL, and students who encounter more English through reading native writers than hearing native speakers informally may assume that it is a ‘neutral’ or ‘formal’ future. In fact the particular native writer or speaker is simply opting to stress certainty rather than arrangement, plan or present evidence.
The intrinsic meaning of WILL is exemplified in:
15. I’ll carry your bag for you.
16. Will you drive me to the airport, please?
17. Peter will leave his mobile switched on in meetings. It’s so annoying when it rings.
These examples show what we might loosely call volition, the willingness or determination of the subject of the modal to carry out the action. Note that  is not about the future, and in  and  the futurity is incidental. It is context rather than words which gives the meaning.
So, our original example can clearly be realized as:
Emma will fly to London next week.
Without expanded context or co-text, we cannot be sure of what is implied by Emma will fly to London next week. If the background has been that she is scheduled to fly next month, but there is an urgent need for her to be in London soon, the speaker of this utterance is indicating Emma’s willingness to fly earlier than intended. In a different context, known to both speaker and listener, the speaker is indicating the certainty of Emma’s flight tomorrow, possibly even because of the speaker’s ownvolition. Outside the context of gap-fill exercises this is not a problem.
5. WILL BE (do)ING (‘Future Progressive’).
WILL BE ….-ING can have two possible overtones, both stemming from the combination of the ideas of certainty (WILL) and limited duration (progressive form).
The first possibility is that the speaker is describing a situation already begun, having duration, and not completed by the time mentioned or implied. This would be explicit in:
At 5 o’clock tomorrow George will be driving down the M1.
The second possibility is that the speaker is more concerned with the pure certainty of the action happening than any volitional aspect that might be implied by the use of WILL by itself. This idea can be illustrated more clearly in the following examples. If someone saysI’d like to know what Andrea thinks about this, responses might be:
I’ll see her tomorrow; I’ll ask her.
I’m seeing her tomorrow. I’ll ask her.
I’m going to see her tomorrow. I’ll ask her.
I’ll be seeing her tomorrow. I’ll ask her.
In all four examples, the I’ll ask her indicates the speaker’s willingness (confirmed by the context) In the first half of the utterance,  indicates the speaker’s willingness to see her,  the speaker’s knowledge of an arrangement already made to see her,  the speaker’s awareness of present evidence of the future meeting and  the speaker’s simple presentation of the fact of the future meeting. It is claimed by some writers, with some justification, that the use of WILL BE ….-ING implies, by its lack of reference to intention, volition or arrangement, a ‘casual’ future.
So, the realization of our standard example can be:
Emma will be flying to London tomorrow.
Depending on the context and co-text, the speaker may be intending a ‘casual’ futurity, or may be indicating a situation in progress at a particular time.
The approach to ways of expressing to futurity outlined in the sections above means that students are far freer to choose for themselves the future form they wish than may appear in some grammars and course books. Far more possible utterances are acceptable than is implied by many gap-fill exercises. However, this is not to suggest that all this is given to the student in one 30-minute “here’s the truth about the future” class. All that is suggested here is that the choice of future form is less arbitrary than sometimes appears, and that teachers aware of this can refrain from over-simple ‘rules’ that may soon confuse the student.
7. Other ways of referring to the future
So far in this paper we have considered the five ways of referring to the future that are considered by some to be ‘tense’ forms: Present Progressive, Present Simple, BE GOING TO, WILL, and ‘Future Continuous’. There are many other ways of referring to future situations, each with its own particular shade of meaning. Some of these are considered briefly in the following pages:
7.1. BE + to + infinitive
This form is not common in informal conversation. It refers to something that is to happen in the future as a plan or decree, normally by some authority other than the subject of the sentence:
23. A new theatre is to be built in Andover next year.
It is common in news reports. In headlines; BE is frequently omitted:
24. Brown to see Obama
7.2. BE + about to+ infinitive
This form is used to refer to planned future events that are expected to happen soon:
25. 300 workers at the Manchester factory are about to lose their jobs.
The soon-ness often carries the idea that the subject is very close to the point of doing something:
26. He looks as if he’s about to turn nasty.
7.3. Other idioms with BE
There are a number of other expressions with BE which have some form of modal-type meaning (ability, obligation, etc), and which point to the future. These include: be able to, be bound to, be certain to, be due to, be likely to/that, be meant to, be obliged to, be supposed to, be sure to.
7.4. Idioms with HAVE
Expressions with HAVE include have (got) to, had better, also withhave some form of modal-type meaning (necessity, obligation, etc), pointing to the future.
27. We’d better get that sorted out tomorrow.
7.5. Other modals
Apart from WILL, discussed in section 4, the other modals are also used with future reference:
28. Do you think you may go skiing again next Easter? (possibility)
29. There might be a few objections to our holiday proposals. (more remote possibility)
30. Can you cope with the kids this afternoon? (ability/possibility)
31. She could leave tomorrow, we’re not sure. (more remote ability/possibility)
32. You must be ready to leave by five at the latest. (obligation)
33. I shall be here all evening. (certainty)
34. Frank should tell Mary before he leaves this evening. (recommendation)
Expressions with WOULD withhave some form of quasi-modal meaning (preference), pointing to the futureinclude: would rather, would sooner, would just as soon.
7.6. Verb (+ to) + infinitive
Some full verbs, such as hope or want, indicate that the action of the complement verb will be in the future (expressing future possibilities). Such verbs are usually followed by the to-infinitive:
35. He hoped to sell his house before the end of the month.