Slide 1

Modals
Hypothetical past
situation


Slide 2

Read the following dialogue attentively.
Sue: Where’s Alec, I wonder? We ought to have
started fifteen minutes ago.
Phil: He may have lost his way. It isn’t very easy to
find this place.
Sam: We should have come here together.
Sue: He could have forgotten all about it, I
suppose.
Kay: He can’t have forgotten, I reminded him only
this morning.
Phil: Well, something must have delayed him.


Slide 3

Sue: Where’s Alec, I wonder?
We ought to have started fifteen minutes ago.
MORAL OBLIGATION

Phil: He may have lost his way. It isn’t very
easy to find this place.
PROBABILITY


Slide 4

Sam: We should have come here together.

WHEN SOMETHING WAS THE BEST THING TO DO

Sue: He could have forgotten all about it, I
suppose.

POSSIBILITY


Slide 5

Kay: He can’t have forgotten, I reminded him
only this morning.
IMPOSSIBILITY (LOGICALLY IMPOSSIBLE)

Phil: Well, something must have delayed him.
LOGICALLY TRUE


Slide 6