第三條件句

第三條件句：if + had + 過去分詞（過去完成時），would have + 過去分詞。用來想像過去本可以有不同的結果——條件和結果都是不真實的，因為事情已經發生了。

縮寫形式：If I'd known（had），I'd have come（would），I would've come。語速快時，would have 聽起來幾乎像 “would-ə”。

💡if 從句裡的 'd 是 had（If I'd known）；結果部分的 'd 是 would（I'd have gone）。另外，would've 聽起來像 “would of”，很多人因此拼錯——書寫時一定要寫 would have。

1. 想像一個不同的過去——實際發生的情況正好相反

• If I had left earlier, I wouldn't have missed the train.

  如果我早點出門，就不會錯過火車了。（我出門晚了，錯過了火車）

• If Lan hadn't helped me, I would have failed the course.

  要不是阿蘭幫我，這門課我就掛了。（但阿蘭確實幫了我）

2. 對過去的事表示遺憾或責備

• If you'd told me it was your birthday, I'd have bought you a cake.

  你要是早告訴我那天是你生日，我就給你買蛋糕了。

• We would have won if we hadn't made so many mistakes.

  要不是我們犯了那麼多錯，我們就贏了。

3. 慶幸壞事沒有發生

• If the neighbours hadn't smelled the smoke, the whole house would have burned down.

  要不是鄰居聞到了煙味，整棟房子都會被燒燬。

• If you hadn't reminded me, I would have forgotten my passport.

  要不是你提醒我，我就忘帶護照了。

結果部分可以用 could have + V3（= would have been able to，本來能夠）或 might have + V3（= would perhaps have，本來也許會）代替 would。

• If we'd booked earlier, we could have sat together.

  如果我們早點訂票，就能坐在一起了。（could have = would have been able to，本來能夠）

• If she had applied, she might have won the scholarship.

  如果她當時申請了，說不定就拿到獎學金了。（might have = would perhaps have，本來也許會）

弄清每個分句說的是什麼時間。說過去的分句 → had V3 / would have V3；說現在的分句 → 一般過去時 / would + 動詞。兩個分句說的是不同時間時，就構成混合條件句。

• If I had studied medicine, I would be a doctor now.

  如果我當初學了醫，現在就是醫生了。（過去 → 現在）

• If we hadn't moved to Da Nang, we wouldn't know each other.

  要是我們當初沒搬到峴港，我們就不會認識彼此了。（過去 → 現在）

• If he were more organised, he wouldn't have forgotten the meeting.

  如果他做事更有條理，就不會忘了那個會議。（現在 → 過去）

• If I didn't have to work tomorrow, I would have stayed at the party longer.

  要不是明天得上班，我就在聚會上多待一會兒了。（現在 → 過去）

💡混合 1 的結果部分常有 now、today、still。看到 “now”，而 if 從句用的是 had V3，結果部分就用 would + 動詞，不用 would have。

在正式英語中，可以省略 if，把 had 放到主語前面：Had I known = If I had known。否定形式是 Had … not + V3（不縮寫成 Hadn't I…）。見“倒裝”一課。

• Had we known the road was closed, we would have gone another way.

  要是我們早知道那條路封了，就會走另一條路了。

• Had she not called, I would have waited all night.

  要不是她打來電話，我就會等一整夜。（不說：Hadn't she called）

• ✗If I would have known, I would have come.

  ✓If I had known, I would have come.

  if 從句用 had + V3。“If I would have…” 在隨意的口語中能聽到，但不是標準用法。

• ✗If I knew you were in hospital, I would have visited you.

  ✓If I had known you were in hospital, I would have visited you.

  說的是過去的事 → had known。

• ✗We were late. If we had taken a taxi, we would arrive on time.

  ✓We were late. If we had taken a taxi, we would have arrived on time.

  結果也是過去的 → would have + V3。

• ✗If she had took the medicine, she would have felt better.

  ✓If she had taken the medicine, she would have felt better.

  had + 過去分詞（taken），不用一般過去時。

• ✗If she had asked me, I would of helped her.

  ✓If she had asked me, I would have helped her.

  would've 聽起來像 “would of”，但一定是 have。

• ✗If it had not rained, we would have play tennis.

  ✓If it had not rained, we would have played tennis.

  would have + 過去分詞。