中2升中3的英文暑假功課問題~Conditionals- should have, would have

When you use should have, you are sure something will happen.
When you use would have, it should be something not taken place.


We will use "would have" when we have "Conditional sentences".


In "(1)If we had taken the earlier flight, we would have died in the plane crash",
First, it is about something in the past. Secondly, the fact (i.e. take earlier flight) did not happen and the second sentance did not take place either (i.e. they died in the plance crash.)
***remember, it is impossible for dead people talking***
***如果我們乘搭更早的航班， 我們已經死在空難***
Hence, this is called "Unreal past conditional" in the family of "conditional sentence"

The Whole pattern should be
past perfect (first part of sentence), would+have+past participle (second part of sentence)

2008-08-25 11:44:25 補充：
should have is usually used in "open present or future conditional", but not in "unreal present or future conditional, unreal past conditionals".

"would+have+ past participle" is used in unreal past conditionals only.

should 是應該(事情發生的機會較小)
would 是會(事情發生的機會較大)