Which modal expresses more certainty, may or might?
None. Both express the same level of certainty.
Jane can't be at work, or she can't be at home. I'm not sure.
Replace both CAN'T with MAY / MIGHT / COULD.
Our son promised to clean his room, but it is still messy.
He (forget / clean) __________________________.
He must have forgotten to clean it.
Past participle of 'forget'
forgotten
Jenna ___________________ (be) sick yesterday since she didn't come to work. (I'm not really certain about this because sometimes Jenna takes a day off to go shopping.)
may have been, might have been, or could have been
Which modal do you use when you are almost 90 or 95 percent sure that something is the case?
must
She might of survived the hurricane if she had stayed indoors.
Change OF to HAVE.
Paul's class starts at 8:30. It's 8:45 and he's not here yet.
He (miss the bus) ______________________________.
He may / might have missed the bus.
Past participle of 'take'
taken
Nick ____________________(lose) over 50 pounds. He looks so thin now. (I am almost certain about this.)
must have lost
Which two modals or similar expressions may be used to express a 50% chance of something being true?
may / might
Ana is smiling. She must have did well on the test.
Change DID to DONE.
Look! Our car isn't in the driveway!
Somebody (steal) _________________________________.
Somebody must have stolen it.
Past participle of 'forbid'
forbidden
The package that I was expecting ____________________ (arrive) today because I don't see a box sitting in front of my door. (I am slightly less than 100% certain about this.)
could not have arrived
Which modal is used to express a possibility which is one of many? This form is not as strong as might or may. It is just one of a number of possibilities.
a) could
b) couldn't
c) must
Could
Dude A: "Hey, what do you think happened at Stonehenge?"
Dude B: "I don't know man. It should have been something to do with aliens."
Replace SHOULD with MAY / MIGHT.
I saw a strange light in the sky last night.
It _________________ a UFO. I don't believe in those things.
It couldn't/can't have been a UFO.
Past participle of 'go'
Mr. Johnson _____________________ (murder) his wife! He is a very nice man. (I believe this is impossible.)
couldn't have murdered
Which two modals or similar expressions may be used to express an almost 95 % certain negative assumption. (when something is almost impossible)
can't, couldn't
Are you joking? David might have gone to Paris last week. He doesn't have enough money to go to Europe.
Change MIGHT to CAN'T or COULDN'T
Imagine that you go to your friend's house, but when you knock on her door there is no answer. You then notice that her car is not there, so the conclusion you come to is that she...
... must have gone out.
Past participle of 'drink'
drunk
____________________ he ______________________(shoot) her?
Could he have shot her?