must／should／could have ＋ p.p.

助動詞＋ have ＋ p.p.：對過去的推測和後悔

Modal + have + p.p. — English grammar, senior high

接續

must have p.p.（當時一定…）・can't have p.p.（當時不可能…）・should have p.p.（當時應該…卻沒有）・could／might have p.p.（當時可能…）

must have p.p. (surely did) · can't have p.p. (surely didn't) · should have p.p. (ought to have, but didn't) · could / might have p.p. (possibly did)

對過去的事推測或後悔：The ground is wet. It must have rained.（地是濕的，一定下過雨。）I should have brought a jacket.（我早該帶外套的。）He might have missed the bus.

For guesses and regrets about the past: The ground is wet. It must have rained. I should have brought a jacket. He might have missed the bus.

shouldn't have p.p. 是「當時不該…卻做了」：You shouldn't have said that.
shouldn't have p.p. means you did it but shouldn't have: You shouldn't have said that.

✗ She must has left already.
✓ She must have left already.
助動詞後面一律用 have。
After a modal it's always have.
✗ I should studied harder.
✓ I should have studied harder.
後悔過去的事用 should have ＋ p.p.。
Past regret: should have + p.p.

You must have been tired after the long flight.

長途飛行後你一定很累吧。

We should have booked the tickets earlier.

我們應該早點訂票的。

He can't have finished already — he only started an hour ago.

他不可能已經做完了，他一小時前才開始。

在 Hanabiの小天地聽例句的錄音、做 3 題練習，答對 2/3 就算學會，進度會記下來。