Sample PPT for TESL5650

1. Past Modals of Deductions

2. Examples of Past Modals of Deductions
Someone may have used
his credit card.
He might have gotten his
credit card stolen.
He can’t have been happy.

3. Form: Past Modals of Deductions
Jane’s phone may have been hacked.
might have
could have
(subject)
(modal verb + have)
(past participle)

4. Meaning: Past Modals of Deductions
0% 50% 99%
may have
might have
could have
couldn’t have
can’t have
must have
Had to have
- Past Modal of Deductions are used to make guesses about
the past.
- ”must have” and “had to have” are deductions that are very
certain. It is not 100% but close!
Impossibility possibility certainty

5. Use: Past Modals of Deductions
Be careful!
He must have gone to the park.
(I’m sure he went to the park).
He must have a driver’s license to drive.
(He needs a driver’s license. It is a requirement)
Deduction
Obligation
* NOT THE SAME GRAMMAR!

6. TIME TO PRACTICE!