There are two aspects within realis future:

. established (es), a regular occurrence: -s

. particular (pa), a non-regular or special occurrence: is -ing

Each will normally be accompanied by an adverb referring to future time. The difference in meaning can be seen in:

(1es) I get paid tomorrow

(1pa) I’m getting paid tomorrow

Sentence (1es) would be said if tomorrow is Friday and I get paid every Friday (this is an established part of my employment). Sentence (1pa) would be appropriate if I don’t get a regular pay-cheque since I only do casual work but this week I did complete a time sheet and thus do expect to get paid this particular Friday.

Another example is:

(2es) We have a meeting this afternoon

(2pa) We’re having a meeting this afternoon

Sentence (2es) could be said on Wednesday morning, as a reminder that there is each week a meeting on Wednesday afternoon; this is an established practice in the workplace. In contrast, (2pa) implies that a particular meeting has been organized, outside the normal schedule.

In essence, established future describes some event which is typically regular and expected. Particular future refers to a ‘one-off’ event, perhaps specially arranged. There are some instances where only the established future is possible. For example, one can say (3es) but not (3pa).

(3es) The sun rises at 7.06 tomorrow morning

(3pa) *The sun is rising at 7.06 tomorrow morning

Sentence (3pa) sounds as if the sun can rise at whatever time it chooses, at its whim.

Suppose that at 9.50, someone inspects a cuckoo clock and expresses a desire to see the cuckoo pop out and sing. The clock’s owner could reply with (4es) but scarcely with (4pa).

(4es) The cuckoo comes out at ten o’clock

(4pa) *The cuckoo is coming out at ten o’clock

Sentence (4pa) sounds as if the cuckoo makes its own decision as to when it will emerge and has notified the owner that this will be ten o’clock.

An alternative to (4es) could be:

(4es’) The cuckoo comes out on the hour

This is ambiguous between established future and a variety of generic. We can now illustrate situations where only the particular future is

allowed. For example, one could say (5pa) but scarcely (5es).

(5pa) She’s having a baby in June

(5es) *She has a baby in June

Sentence (5es) sounds as if it is an established event—she has a baby every June. (Note that it is possible to say She’s having her baby in June. It must already have been established that she’s having a baby, and this sentence then specifies the month.)

As a further example, one is more likely to hear (6pa) than (6es).

(6pa) We’re having our own house next year (our insurance policy matures next year, and we’ll use the money as deposit against a mortgage for a new house)

(6es) *We have our own house next year

It would be possible to invent a situation for which (6es) would be appropriate. It might involve the unlikely scenario of an authoritative government allowing each family to have their own house every fifth year, and next year being our turn. But in a normal world, (6es) is infelicitous.

The contrast between irrealis prediction (pred), shown by will which is often called ‘future’—and the realis futures can be seen in:

(7es) *It rains tomorrow

(7pa) *It is raining tomorrow

(7pred) It will rain tomorrow

No reality can be attached to rain falling tomorrow, so that neither of the realis futures are possible. All one can do is make a prediction, which may or may not come true.

There are, of course, will-versions of the other examples just given. It sounds odd to say She will have a baby in June. However, the following is acceptable:

(5pred) She will have a baby quite soon (when she got married, she said they planned to start a family right away)

This is a prediction, lacking in reality; it implies that she has yet to conceive (and may be unable to). If she has been confirmed as pregnant, then only She’s having a baby quite soon is appropriate.

Sentences with will convey a prediction that something will happen; it is never a certainty and often bears qualification. For example:

(4pred) The cuckoo will come out at ten o’clock (if the repairman who just left has done his job properly)

(1pred) I’ll get paid tomorrow (if the computer system doesn’t break down again)

(2pred) We’ll have a meeting this afternoon (if enough people turn up to ensure a quorum)

Sometimes a prediction is as good as certain. But there is always some miniscule element of doubt. While listening to the ranting of a maniac I might well respond to a question about the time of sunrise with:

(3pred) The sun will rise at 7.06 tomorrow morning—if indeed, the world doesn’t end before then, as this fellow is predicting it will

There is an idiomatic particular future. When called to come, someone could reply:

(8pa) I’m coming in a couple of minutes

Or the time adverb may be omitted, giving just:

(8pa’) I’m coming

The person who says this may not actually be in the process of coming (as one would expect if I’m coming were interpreted—in the absence of a time adverb—as actual imperfective present). They may still have a couple of sentences to write in finishing a letter, before putting on shoes and coat and then coming. But by conventional usage, (8pa’) is used as and interpreted as particular future. A similar example is He’s moving to Lisbon in a few weeks. The time adverb in a few weeks could be omitted and He’s moving to Lisbon would be interpreted as a particular future relating to some time not far ahead.

There are rather few instances of time adverb being omissible from a realis future. Another relates to (5pa); one can say, just, She’s having a baby. And the established future Tomorrow is Wednesday does not require a time adverb since the copula arguments tomorrow and Wednesday provide sufficient temporal specification.