Structure 2013-08-16

p. 272
A
1 evidence
2 contribute
3 estimate
4 speculate
5 conclusion
6 encounter
perhaps = maybe
skeptical (sceptical - BrEng) = not wanting to believe something without enough evidence
gullible = believing something too easily without evidence; easy to lie to
B
1 certain - "must have believed"
2 possible - "might have marked"
3 impossible - "could not have been"
4 certain - "had to have built"
---
Where was he yesterday?

Maybe he was at home.
     = He could have been at home.
     = He may have been at home.
     = He might have been at home.
Maybe he was not at home.
     = He may not have been at home.
     = He might not have been at home.
- These are possible explanations.

It's impossible that he was at home.
     = He couldn't have been at home.
- This is not a possible explanation.

He was probably at home. / I'm pretty sure he was at home.
     = He must have been at home.
     = He had to have been at home.
He was probably not at home. / I'm pretty sure he wasn't at home.
     = He must not have been at home.
---
Was he at home yesterday?
- He may have been. / He must have been. / etc. (with "been")

Did she do her homework?
- She may have. / She must have. / etc. (no past participle)

(Questions are in the simple past. We can answer with a perfect modal if we are not 100% sure.)
---
I bought a lottery ticket yesterday.  I may have won.
= It is really possible that I won. I just don't know yet.

I should have bought a lottery ticket. I might have won.
= It is certain that I didn't really win. It *was* possible to win, but I didn't buy the ticket.

("may" is only for real possibility, "might" can be real or unreal)
---
Exercise 1
1 e - very certain
2 d - very certain
3 h - uncertain (it's possible he wrote other books, but I don't know)
4 c - uncertain
5 f - very certain
6 b - uncertain
7 a - very certain
8 g - very certain
---
subject + modal + have + past participle
---
Exercise 2
1 made (past participle)
2 carved (past participle)
3 have (could + base form)
4 must (he was certain about this)
5 could (questions rarely use "may have" or "might have")
6 have (might + base form)
7 have drawn (conclusion about the past)
8 could (they showed that it was possible)
9 Could (+ have + past participle)
10 have (could + base form)
Could they have carved the statues?
Did they carve the statues?
---
Homework: p. 276 Exercise 3
---
hoax: a trick to get people to believe something that isn't true
fraud: when you lie to someone in order to get money