全時態推測

🎯 這一課你會學會

把 B1 學的推測(must be / can't be / might be)擴到所有時態——對現在、正在進行、過去、過去進行中的事,都能有把握地推測。學完你能「根據線索判斷」任何時間點的情況,也說得出自己有幾分把握。

💬 先聽一段對話

Mia: Jun's not here and his coat's gone.（Jun 不在,外套也不見了。)
Amy: He must have left already.（他一定已經走了。)
Mia: But his coffee's still warm.（可是他的咖啡還溫的。)
Amy: Then he can't have gone far. He might be talking to someone outside.（那他不可能走遠。他可能在外面跟人講話。)

🔑 推測的三個確定度 × 四種時間

確定度不變(must 幾乎確定是 / can't 幾乎確定不是 / might·may·could 可能),變的是後面的動詞形式:

講的是…	形式	例句
現在狀態	must be	He must be tired.
現在正在進行	must be doing	He must be sleeping.
過去(已發生)	must have + PP	He must have left.
過去某時正在進行	must have been doing	He must have been working.

(把 must 換成 can't / might 也一樣。)

🧩 文法點:一套邏輯,四種時間

① 現在:情態 + be(+ 形容詞/地點/-ing):

• She must be at home.（現在一定在家)
• She must be sleeping.（現在一定在睡——be + -ing)

② 過去:情態 + have + 過去分詞:

• She must have gone home.（一定回家了)
• He can't have known.（不可能知道)

③ 過去進行:情態 + have been + -ing:

• The ground's wet — it must have been raining.（剛才一定在下雨)
• I called but no answer; you might have been sleeping.（你當時可能在睡)

④ 否定確定仍用 can't(不是 mustn't)——B1 的鐵律延續:

• ✅ He can't have finished so fast.　❌ He mustn't have finished.

⑤ 訣竅:先決定「多確定」(must/can't/might),再決定「什麼時間」(be / be doing / have done / have been doing)——兩個一組就對了。

📒 高頻單字

單字	KK 音標	中譯	例句
obviously	/ˈɑbviəsli/	顯然	Obviously, he's gone.
clue	/klu/	線索	There's no clue.
judging by	/ˈdʒʌdʒɪŋ baɪ/	從…判斷	Judging by the mess…
apparently	/əˈpɛrəntli/	看來、據說	Apparently, they left.
seem	/sim/	似乎	It seems likely.

🗣️ 發音提醒

• must have → must've /ˈmʌstəv/;can't have →「KANT-əv」;must have been →「MUS-təv-bin」。
• apparently /əˈpɛrəntli/:重音在 pa,「a-PARE-ənt-lee」。
• 這些連讀在聽力裡很常見——認得 「must've been」= must have been 很重要。

✍️ 開口練習

練習 1:選對時間形式。

• The lights are off — they ＿ (must/leave). 過去 → must have left
• Look, he ＿ (must/study) right now. 現在進行 → must be studying
• His hands are dirty; he ＿ (must/work) in the garden. 過去進行 → must have been working

練習 2:看線索推測(現在 + 過去各一)。

The kitchen is a mess — someone must ＿. The oven's still hot — they can't ＿.

練習 3:用 might have been + -ing 猜一件過去正在進行的事。

🎒 帶走

• 推測 = 確定度(must/can't/might)+ 時間形式(be / be doing / have done / have been doing)。
• 現在(be)、現在進行(be doing)、過去(have done)、過去進行(have been doing)——一套邏輯套四種時間。
• 否定確定用 can't(延續 B1 鐵律)。

🎉 你完成 B2 Unit 4「情態與推測進階」了!
needn't have、全時態推測——你的判斷與語氣細膩到位了。下一個 Unit,把句子雕得更精緻:縮減關係子句、分詞構句、進階連接。