Degree of
certainty is how we use modals for explaining how much our certainty about
something, how sure we are (certainty, probability, possibility, and
impossibility).
11. Degree
of certainty : present time
If
you are sure about what you said, you can use to
be/verb (100% sure)
Ex:
->
why is not Jane in class ?
*Jane
is sick ( I am sure that Jane is sick. Last night, she said to me she
would not come to class because got flu)
->
do you know where Jane goes ?
*
Jane goes to market ( I just met
her in road, she would buy eggs for her mom, she said)
Must (95%) expresses
a strong degree of certainty, but less than 100%.
It
can be logical conclusion.
Ex:
*Jane
must be sick ( usually she is in the class every day, but I saw her last
night, she was not feeling good)
*Jane
must go to market ( I just saw her in the road, she walked to market)
May/
Might/Could (less than 50%) it just
expresses a guess, maybe, perhaps(possibility).
Ex:
*Jane may/might/could be
sick ( I do not really know, she may be at home watching tv. She
might be at library or she could be out of town)
2. Degree
of certainty: present time negative
-> ”there
is a party at John’s home” Why does not Jane eat ?
*she
is not hungry (she said, she just
ate before went here)
Could not/can not (99%)
it will be impossibility
*she
could not/can not get hungry ( it is impossible. I just saw her
eating 4 pieces of pizza and she wanted
to eat again ? I do not believe it)
Must not(95%) logical conclusion
*she
must not get hungry ( Jane is not eating
her food. That is the only reason I can think of.)
May not/might not(less than 50%)
*she
may not/might not get hungry. (I do not know. I just came here. She
might not be feeling good or she has
eaten before I came.)
3. Degree of certainty : past time
It
has the same certainty. Just about
time(past)
The
formula : modal + have +(been or V3)
->Why was not Jane in the class ?
*
she was sick
*she
must have got sick
*she
might/may/could have got sick
Note
: simple way to understand is it depends who is speaking up. It might be different
for everyone.
Where
does Siska go ?
Asep
: she goes to library. I just met her.
Jamal
: she must go to library because she will persentate tommorrow.
Permana
: I dont really sure. She might go to library
I
hope it will help you to undersand. Thanks for have visited my blog.
See
you in the next post.
Reference
: Betty Schrampfer Azar, English Grammar-Third Edition
