2016-09-12 Grammar: present and past inference

Greg Malivuk
[email protected]
http://www.pastebin.com/u/gmalivuk - Notes from all my classes
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Homework: p. 262 exercise 5 (1-5 only)
1 a may/might/could
  b may/might/could
  c may/might could
	(These are three possibilities of who might be at the door.)
2 a shouldn’t/couldn’t/can’t
  b couldn’t/can’t
  c couldn’t/can’t
  d must
	(The person is eliminating other possibilities and concluding that it’s a salesperson.)
3 a may not / might not
  b should
  c must (“should” is for near-future predictions, more than for conclusions about the present)
4 a must
  b may/might/could
  c may/might/could
  d couldn’t/can’t
  e must not (conclusion from the fact that they fight all the time)
5 a must (It must be somewhere, because if it’s not somewhere, it’s nowhere, which is impossible.)
  b couldn’t
  c should / may/might/could (“I usually put it” means this is a good or the best explanation, so “should” is okay)
  d may/might/could (Because I usually put it on my desk, this is *not* the best explanation, but it is another possibility.)
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must - This is the only explanation.
should - This is the best explanation.
	shouldn’t - This isn’t the best explanation.
may (not)/might (not)/could - This is one explanation.
must not - This is not an explanation.
couldn’t - This is impossible.
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“should” is complicated, because it’s sometimes a real prediction (“The weather should be nice tomorrow.”) but other times it’s an unreal expectation (“My wallet should be on this table. I don’t know where it went.”)
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p. 263 exercise 6 - Are these inferences or predictions? What modal is correct?
1 inference - must
2 inference - must
3 prediction - will or may/might/could
4 prediction - will or may/might/could
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prediction and inference about the past (p. 264)
- Modals for inference have the same basic meaning when they’re about the past, we just need to add
	“have” and the past participle instead of using the base form of the verb.

He just ran the marathon. He must be tired. (inference about now)
He had just run the marathon when I saw him yesterday. He must have been tired. (inference about the past)

must have - This is the only explanation (about something in the past).
should have - This is the best explanation.
	shouldn’t have - This isn’t the best explanation.
may (not)/might (not)/could have - This is one explanation.
must not have - This is not an explanation.
couldn’t have - This is impossible.
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The keys should be on the table.
	- I expect them to be there. Go check.
	- I thought they were there, because that’s where I put them, but they’re not on the table.
	- The table is the place where I suggest that you put the keys every time.

The keys should have been on the table.
	- I’m pretty sure that’s where they were. Did you check the table?
	- I thought that’s where they were, but I guess someone moved them.
	- It was a good idea to put them there, but you didn’t.
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p. 265 exercise 8
1 a couldn’t have been (it’s impossible, because he doesn’t have a telephone)
  b could/may/might have been (it’s possible, but not likely because they wouldn’t have called at night)
  c must have been (My brother is impossible and my friends are unlikely, so the most likely explanation is that it was a wrong number.)