早該、一定是、本來可以(過去情態)

🎯 這一課你會學會

把推測和評論用到過去——「你早該打給我」「她一定是忘了」「本來可以更糟」。用 should / must / could / might + have + 過去分詞。這是講後悔、事後判斷最道地的方式。

💬 先聽一段對話

Mia: I waited an hour, but Jun never came.（我等了一小時,Jun 都沒來。) Amy: He must have forgotten. You should have texted him.（他一定是忘了。你早該傳訊息給他的。) Mia: I know. I could have called, but my phone died.（我知道。我本來可以打的,但手機沒電了。) Amy: Oh well. It could have been worse!（唉,算了。可能更糟呢!)

🔑 四個常用(全部 + have + 過去分詞)

• should have + 過去分詞(早該…卻沒,後悔/責備):You should have called.
• must have + 過去分詞(一定是…了,過去的確定推測):She must have left.
• could have + 過去分詞(本來可以…卻沒 / 有可能):I could have helped.
• might / may have + 過去分詞(可能…了,不確定):He might have forgotten.

🧩 文法點:過去的推測與後悔

① 全部都是「情態動詞 + have + 過去分詞」:

• should have gone、must have known、could have been、might have left。

② 各自的意思:

• should have + 過去分詞 = 當初該做卻沒做(後悔/責備):
  • I should have studied.（我當初該讀書——但沒讀)
  • 否定 shouldn't have:You shouldn't have said that.（你不該說那句)
• must have + 過去分詞 = 對過去的確定推測:
  • The ground is wet. It must have rained.（一定下過雨)
• can't have + 過去分詞 = 確定「不可能發生過」:
  • He can't have finished so fast.（他不可能這麼快做完)
• could / might / may have + 過去分詞 = 過去的可能性 / 沒實現的可能:
  • She might have missed the train.（她可能錯過火車了)
  • You could have hurt yourself!（你剛剛可能會受傷!——還好沒)

③ ⚠ 拼字陷阱:是 have,不是 of！

• 口語 should have → should've /ˈʃʊdəv/,聽起來像 "should of",但寫一定是 should have / should've。
• ❌ should of ❌ must of ❌ could of —— 全錯。

④ 跟第三條件是一家人:If I had known, I would have come.（第六課學的)——都用 have + 過去分詞講「沒發生的過去」。

📒 高頻單字

單字	KK 音標	中譯	例句
forget	/fɚˈɡɛt/	忘記(過去分詞 forgotten)	He must have forgotten.
worse	/wɝs/	更糟	It could have been worse.
text	/tɛkst/	傳簡訊	You should have texted.
notice	/ˈnotɪs/	注意到	I should have noticed.
happen	/ˈhæpən/	發生	What could have happened?

🗣️ 發音提醒

• should've / must've / could've /-əv/:'ve 輕輕帶過,別唸成 "of"。
• worse /wɝs/:捲舌 + s,一個音節。
• forgotten /fɚˈɡɑtən/:重音在中間 got。

✍️ 開口練習

練習 1:選對過去情態。

• The lights are off. They ＿ (leave). 一定走了 → must have left
• I'm so tired. I ＿ (sleep) more. 早該多睡 → should have slept
• He ＿ (be) stuck in traffic. 可能塞車 → might have been

練習 2:抓錯(have not of)。

• ❌ You should of told me. → ✅ You should have told me.

練習 3:講一個後悔 + 一個過去推測。

I should have ＿. He must have ＿.

🎒 帶走

• 過去情態 = should / must / could / might + have + 過去分詞。
• should have(早該,後悔)、must have(一定是,確定推測)、can't have(不可能發生過)、could/might have(過去的可能)。
• 寫的是 have / 've,不是 of。

🎉 你完成 B1 Unit 5 的推測部分了! 下一課是這單元的情境收尾:面試與正式 email——把 B1 的工具用在最需要「講得體」的場合。