2015-11-16 Grammar: inferences about the past

Greg Malivuk
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http://www.pastebin.com/u/gmalivuk
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Homework: read p. 264 (inferences about the past), do p. 265 exercise 8
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Do parts 1 and 2 now because you didn’t do the homework.
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1 a couldn’t have been
  b might have been / may have been / could have been
  c must have been
2 a should have had / must have had
  b might have been / may have been / (would have been)
  c might have paid / could have paid
  d must have been

(We don’t use “could” with “be able to”, because they have the same meaning.)

“Peter may have paid.” = Maybe Peter paid. (“may” is always about real possibilities. If something didn’t happen but we’re imagining that it did, we can’t use “may”.)

“You should have done it.” = It was a good idea, but you didn’t do it.
(This is the primary meaning of “should have”. If this meaning makes sense, that’s what the sentence means. If “it was a good idea” doesn’t make sense, then it might be an inference.)
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I wish I had a lottery ticket. I might have won. / I could have won. (imagining an unreal situation)
= It was possible, but it definitely didn’t happen.

Where is my lottery ticket? I might have won. / I may have won. / I could have won.
(Making an inference about a real situation.)
= It was possible, but I’m not sure.
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Look at pictures of obsolete household tools. What could they have been used for?