In our last note on grammar, "A grammatical take on time", we looked at how we express time in English. In particular, we focused on how we indicate that an action took place in the past, or is taking place in the present. In this note, we will look at how we indicate that an action is expected to happen in the future.

Last time, we explained that, grammatically speaking, we express time using a combination of tense and aspect. Tense refers "to the location of a situation in time"(11.4). In English, one way that this location is expressed is in different forms of the verb, which are known as 'verb inflections'. From a strictly grammatical point of view, in which tense is defined as being shown by a verb inflection, English has only two tenses: the simple present and simple past:

Simple present: I, you, we and they laugh; He or she laughs
Simple past: I, you, he, she, we and they laughed

Aspect, on the other hand, "refers primarily to the way that the time of the situation is regarded rather than its location in time in absolute terms"(11.4). It is expressed by the use of an auxiliary verb ('be' or 'have') with the main verb. In English, there are two aspects: one where the action is considered as continuing (progressive aspect), and one where the action is considered complete (perfect aspect).

Progressive aspect: I am laughing
Perfect aspect: I have laughed

Let's look now at how we indicate future time in English. Unlike the simple present and simple past, future time is considered an aspect of modality and not of tense. Modality is concerned with assertions of probability, possibility, permission, intention, obligation and the like (4.2.2).

If we examine sentences that are commonly thought of as being in the future 'tense', we can see why they are actually expressions of modality; for example:

Barack Obama will be a popular US president.

This statement is an assertion about what the speaker believes, hopes or expects will happen in the future. Statements about the future, unlike those of the past and present, cannot be declarations of fact. They are, therefore, regarded as modal in nature.

The example illustrates how we express modality in English: a word called a 'modal auxiliary' (or 'modal') is inserted before the verb. In the example, the modal auxiliary is will, which is placed before the verb be. 'Will' is one of the most common auxiliaries used to indicate the future.

The other modals are: 'can' (past tense 'could'), 'must' ('must'), 'shall' ('should') and 'may' ('might'). Some of these also can express the future; for example:

You shall do as you're told.

I must come today before I forget!

As we saw with the Barack Obama example, the modal comes immediately before the verb (will+be). So, in the two sentences above, shall appears before do and must appears before come. (The picture is slightly different with negative sentences and questions, but that's another topic.)

Another common way to express the future is with the phrase 'be going to', using the relevant form of the verb 'to be'. Again, it is inserted just before the verb:

They are going to broadcast more details about the crisis as they come to hand.

The phrase 'be going to' is a semi-auxiliary verb. There are other semi-auxiliary verbs and auxiliary-like verbs that are used to express the future, such as 'be about to', 'be certain to', 'have to' and 'had better'. Auxiliary-like verbs are so named because they behave like auxiliary verbs in indicating time, aspect and modality (11.17).

In future notes on grammar, we will look in more detail at verbs and auxiliary verbs.

Reference: Sidney Greenbaum: The Oxford Reference Grammar, edited by Edmond Weiner, Oxford University Press, 2000.