General English C1 · Lesson 4B

Grammar Bank

The rules behind this lesson — form, use, model sentences and the mistakes to avoid.

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Grammar focus of this lesson

speculation and deduction

1 structure

Speculation and deduction
Grading certainty about the present and the past.
I've got this
Rules & form
- ›Certain: must / can't (+ have + participle for the past).
- ›Possible: may / might / could (+ have).
- ›Continuous forms: She must be waiting / must have been waiting.
- ›Other exponents: is bound to, is unlikely to, there's every chance.
- ›be supposed to / apparently for reported evidence.
Examples
- “They can't have read the brief — half the requirements are missing.”
- “It might well have been a data-entry error.”
- “He's bound to ask about the margin.”
Watch out · For the negative deduction use can't have, not mustn't have.
Your own example