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Complex modality and speculation
C2 C2 grammar · lesson 8 of 12
At C2 you can express exactly how sure you are about past, present and future events by combining modals with perfect, continuous and passive forms, and with words like well and bound.
The full modal system
You know the basic modals of deduction (must, might, can’t + have done). At this level you combine them freely with continuous and passive forms and adjust certainty with extra words.
| Time / form | Pattern | Example |
|---|---|---|
| Present continuous | modal + be + -ing | She must be working late. |
| Past simple | modal + have + past participle | He can’t have seen the email. |
| Past continuous | modal + have been + -ing | They might have been joking. |
| Past passive | modal + have been + past participle | The file may have been deleted. |
| Future/general | be bound to / be sure to / be likely to | Prices are bound to rise. |
Fine-tuning certainty
Well after may/might/could makes the possibility stronger: She might well win = it is quite likely. Just makes it weaker or surprising: It might just work. Easily stresses that something was very possible: Someone could easily have fallen. Can’t possibly and couldn’t conceivably make a negative deduction stronger.
Ken isn’t answering. He must be driving.
The road is wet – it must have been raining overnight.
The painting can’t have been stolen; the alarm didn’t go off.
Mia may well have been right all along.
That could easily have been a serious accident.
The new rule is bound to cause confusion at first.
You can’t possibly have finished already!
The plan is risky, but it might just succeed.
Could have: two meanings
Could have done can express a past possibility (He could have taken the earlier train – I’m not sure) or an unused ability or option (He could have taken the earlier train, but he chose not to). Context tells you which. Similarly, should have can be criticism or expectation: The parcel should have arrived by now (= I expected it to).
Speculating in formal writing
In reports, modal verbs are often combined with hedging: The decline may well have been caused by several factors; This is likely to have contributed to the problem.
✗ She mustn’t have heard the bell.
✓ She can’t have heard the bell.
✗ They might have been knew the answer.
✓ They might have known the answer.
✗ The window must have broken by the wind.
✓ The window must have been broken by the wind.
✗ He must be work at home today.
✓ He must be working at home today.