2022-01-07 17:56:00
Further reading on the uses of
must and
can't (for deduction) CERTAINTY ABOUT THE PRESENT
When making deductions about the present:
- We use "
must" when we are almost 100% sure that something
is True.
- We use "
can't" when we are almost 100% sure that something
is Impossible.
For example, Alex works from 8:00 am to 2:00 pm every day, now it is 10:00 am. We can say:
- He must be at work. (We are almost 100 % sure that he is at work because he has been there since 8:00 am.)
We can also say:
- He can't be at home. (We are almost 100 % sure that it is impossible for him to be at home now because he has been at work since 8:00 am.)
CERTAINTY ABOUT THE PAST
When making deductions about the past:
- We use "
must have" when we are almost 100% sure that something
was True.
- We use "
can't have" when we are almost 100% sure that something
was Impossible.
For example, John, who works from 8:00 am to 2:00 pm, was at work yesterday. We were walking by his house yesterday at 10:30 am. My friend said: "Let's visit John". I was sure that it was impossible to find him at home because he works at this time. So, we can say:
We rang his doorbell, but no one answered.
- He must have been at work. (We are almost 100 % sure that he was at work at that time.)
We can also say:
- He can't have been at home. (We are almost 100 % sure that it was impossible for him to be at home at that time.)
https://t.me/English_Grammar_in_Use_5th
2.1K viewsAdmiral, 14:56
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