A speculation-and-deduction warm-up for B2 learners. Open a case, read the clues, and argue your theory using modal verbs of speculation — must be, might have, can't have, and the rest.
Click “Open New Case” above to reveal your first situation.
What's your theory? Discuss with your group — every sentence needs a modal verb of deduction.
Possible theories
| Certainty | Form | Example |
|---|---|---|
| Almost sure | must be | She must be the manager — she's giving all the orders. |
| Possible | might be / could be / may be | She might be a new employee, or she could just be visiting. |
| Almost impossible | can't be / couldn't be | She can't be in charge — she looks as confused as everyone else. |
| Certainty | Form | Example |
|---|---|---|
| Almost sure | must have + p.p. | He must have forgotten his keys again. |
| Possible | might/could/may have + p.p. | He might have left them at work, or he could have dropped them. |
| Almost impossible | can't have / couldn't have + p.p. | He can't have lost them — he had them ten minutes ago. |
It's possible that…Perhaps / Maybe…I'd guess (that)…I reckon…There's no way…My theory is that…Knowing her/him, …On the other hand, …