English · Chapter 17 · Lesson 5 · Grammar primer
Modals of deduction
How English guesses out loud - must be, might be, could be, can't be - and why 'mustn't be' is not the opposite of 'must be'.
The lesson is a long-form read rather than a flashcard session. Open the primer below, work through it once, then come back and continue with the next lesson.
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