Modal verbs: Has their use declined?

verbModal verbs: how their use has declined in recent times

As is well-known, English has a number of core modal verbs, including can/could, will/would, shall/should, may/might, and must. These make it possible for us to express meanings such as ‘possibility’, ‘necessity’, ‘obligation’, ‘permission’, and the like. The use of the modal verb must has declined over recent decades. A very likely reason for this is that speakers have become less willing to impose obligations on others, or to be seen to be imposing obligations, even in situations when they are entitled to do so.

What about the other modal verbs in English? The table below shows how their use has declined across the board in written and spoken British English between the 1960s and the 1990s:*


Modal Written British English 1960s–1990s
Change in %
Spoken British English 1960s–1990s
Change in %
would -11.7% -7.1%
will -4.2% +12.8%
could +1.4% -11.9%
can +2.9% +6.8%
might -17.9% +5.1%
may -17.6% -39.8%


-11.9% -14.1%
shall -43.7% -48.6%
must -29.1% -54.2%
Total -9.6% -6.4%

Changes in modal usage, calculated as a percentage change per million words of text. Bold figures are statistically significant.

Notice first of all that the rate of change is different for the various modals in written and spoken English. For example, the use of can has increased more in spoken than in written English. This may be due to speakers using this verb more often to ask for permission than may, which has declined in use.

Let’s now take a closer look at shall, which is much more common in British English than in American English. Like must, it has also dropped dramatically in use. When used with first person subjects shall is used interchangeably with will:

I shall look into this.

I will look into this.

Is there a difference between these two ways of talking about a future event? From a stylistic point of view there is: the first of these alternatives sounds more formal, and is more likely to be used by older speakers. However, there is really no difference in meaning: both sentences are used to speak about a situation in the future.

Not everyone would agree with what I just wrote. Some writers would say that with first person subjects (I/we) will should be used to convey an element of volition, whereas shall should be used to talk about a neutral future. With other persons (he, you, they, etc.) shall should be used for promises/guarantees (Cinderella shall go to the ball), in ‘regulatory language’ (Students shall not enter the premises after midnight), or to express strong volition (You shall not smoke here). The journalist Simon Heffer explains the difference with a well-known anecdote in his book Strictly English (2012):

The Victorian schoolmaster had a way of impressing this distinction upon his charges, with the story of the boy who drowned: for he had cried out ‘I will drown, and no-one shall save me’.

Heffer regrets the fact that speakers no longer know how to use shall and will in the right way. Maybe it’s true that a useful distinction in English is lost. However, another way of looking at this development is to recognize that the language has changed in such a way that the difference between shall and will (other than in questions) is slowly disappearing because speakers no longer sense a meaning difference between these verbs. This would mean that speakers need only one verb, and it looks like will has won out. The increased use of will shown in the table above supports this hypothesis, but the increase is not as high as you would expect, so perhaps the table only offers a partial explanation for the trends in usage. What’s interesting is that the decline of shall is slightly higher in spoken English than in written English. This may well mean that the decline will spread in the future because changes in spoken language often make their way into written language.

Bas Aarts is Professor of English Linguistics at UCL and the author of the Oxford Modern English Grammar. He is also a founder of the free Englicious website with free literacy resources for teachers of English.

* The data are from Bas Aarts, Jill Bowie and Sean Wallis (2015) Profiling the English verb phrase over time: modal patterns. In: Irma Taavitsainen, Merja Kytö, Claudia Claridge and Jeremy Smith (eds.) Developments in English: expanding electronic evidence. (Cambridge: Cambridge University Press) and from Geoffrey Leech, Marianne Hundt, Christian Mair, and Nicholas Smith (2015) Change in contemporary English: a grammatical study (Cambridge: Cambridge University Press).


Author: Oxford University Press ELT

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2 thoughts

  1. Only native speakers know the difference in meaning concerning modal verbs.
    As I’d like to ask you about the difference between may and might.
    Which one is more possible? .
    Can I say I think I must go home.
    I think +I must +stem…ect.
    is this structure true?
    Is it formal or informal?.

  2. We’re missing data here. Rather than representing a decline in willingness to oppose obligations, it could just be that ‘must’ is being replaced by ‘need to’ and ‘have to’.

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