2017-09-07 Grammar: modals of inference

Greg Malivuk
[email protected]
http://www.pastebin.com/u/gmalivuk - notes from all classes
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Homework: read p. 258 (focus 1) of the new handout and do p. 260 (exercises 3 and 4), but write only one sentence for each number.
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A logical inference is a conclusion I make based on some evidence, but I don’t know the information directly. I can be sure or unsure about my inferences.
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You just ran a marathon. You must be very tired. - I’m very sure about this. I would be surprised if you said you weren’t tired.
You left the party early. You may be tired. - I’m not sure, but this is one possibility I can think of.
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The meanings of “must”, “should”, and “may”/”might”/”could” are somewhat similar for advice and for inference:
must (advice) = this is your only option
must (inference) = this is the only explanation
should (advice) = this is the best option (but not the only one)
should (inference) = this is the best explanation (but not the only one)
may/might/could (advice) = this is one option
may/might/could (inference) = this is one explanation
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p. 262 exercise 5 - With your partner, complete the paragraphs with the correct modals of inference.
1 a should
  b may/might/could
  c may/might/could (The postal carrier and salesperson are other possibilities.)
2 a can’t
  b shouldn’t
  c couldn’t/can’t
  d must
3 a may not / might not
  b should
  c must
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I can use the same words for inferences about the past:
You ran a marathon yesterday. After that, you must have been tired.
- After the modal, use “have” and the past participle of the verb to make inferences about the past.
Change exercise 5 number 2 to the past:
Someone was ringing the doorbell. It couldn’t have been my brother; he had a key. It shouldn’t have been the postal carrier; he didn’t usually ring the bell. It couldn’t have been a friend; all my friends thought I was still in New York. It must have been a salesperson. I didn’t answer it.
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Homework (optional): p. 266 exercise 9 - Use modals from this lesson to give possible explanations for the situations.