Modal verbs of deduction

There are facts and there is what we think about facts

All modal verbs can be used to express deduction. That is, when we express what we think we know, as opposed to what we know.

And they behave differently. They have continuous, passive and past forms that are constructed with the continuous infinitive (be doing), passive infinitive (be done) and perfect infinitive (have done). These forms are notably different to standard constructions.

For example, the standard past of he can’t do is he couldn’t do but the deductive version is he couldn’t have done.

Notice that there is not much distinction between ‘may’ and ‘might’ for possibility, which usually look into the future—it may/might rain later—and the same verbs for deduction, which generally refer to the present—he may/might be at home.

Both ‘may’ and ‘might’ are used for past deduction: the butler may/might have killed her (i.e. perhaps the butler killed her). But only ‘might’ is used for the unreal past: you might have killed yourself (i.e. you didn’t kill yourself, but you took a terrible risk).

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Peter Brook at the Teatro Valle Occupato

A great British director in Rome


Peter Brook is one the great theatre directors of the twentieth century. His 1970 production of A Midsummer Night's Dream made theatre history.

On Friday April 12 at 8pm the Teatro Valle Occupato is screening 'The Tightrope', a documentary about Brook by his son, Simon Brook. The film will be followed by a public debate with Peter Brook.

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