Advanced English · 20 min
Modal perfects
The point
A modal plus have plus the past participle looks back. Should have is a past duty that was missed. Must have is a strong guess about the past. Might have is a weak guess. The participle is required.
Form and use
A modal perfect is a modal plus have plus the past participle. It looks back at the past from the present. The modal changes the meaning. The have and the participle stay fixed. Do not use has, and do not drop have.
Meanings: must have left — a strong conclusion about the past might have left — a past possibility could have left — a past possibility, or an unused ability should have left — the right past action, which did not happen would have left — the imagined result of a past condition can't have left — a strong conclusion that it did not happen needn't have left — someone did it, but it was not necessary Each line is modal plus have plus the participle: she must have taken the file.
Pair the near neighbors. Must have and can't have are strong and opposite: I am sure it happened, I am sure it did not. Might have and could have are weaker. Should have criticizes or regrets. Needn't have means the action happened but was wasted. Don't have to, by contrast, talks about no obligation now or in general, not about a wasted past act.
Form errors are small and serious. She must has left uses has. She should have leave uses the base. She must had left drops the modal pattern. Say must have left, should have left, needn't have left. Questions invert the modal: Could she have known? Should we have waited? Negatives: she can't have known, she should not have waited.
Don't translate it like this
Don't say
She should sent it.
Say
She should have sent it.
그녀는 그것을 보냈어야 했습니다.
Should have plus the participle.
Short examples
She should have sent it.
그녀는 그것을 보냈어야 했습니다.
She must have left.
그녀는 떠났음에 틀림없습니다.
She must have taken the file.
그녀가 파일을 가져간 것이 틀림없습니다.
She might have left early.
그녀는 일찍 떠났을지도 모릅니다.
He could have finished it, but he did not.
그는 그것을 끝낼 수 있었지만 끝내지 않았습니다.
You should have checked the date.
날짜를 확인했어야 했습니다.
We would have waited if we had known.
알았더라면 기다렸을 것입니다.
She can't have known the code.
그녀가 코드를 알았을 리가 없습니다.
You needn't have brought a copy.
사본을 가져올 필요는 없었습니다.
Could she have known?
그녀가 알았을 수 있습니까?
Questions
Every question has to be right to close this point.
Answer every question, then check.