If I had …, I would have …

與過去事實相反的假設

Unreal past: If I had …, I would have … — English grammar, senior high

接續

If ＋主詞＋ had ＋ p.p., 主詞＋ would／could／might have ＋ p.p.

If + subject + had + p.p., subject + would / could / might have + p.p.

說「過去沒有發生，如果當時…就會…」：If I had studied harder, I would have passed the exam.（如果我當時更用功，就會通過考試了。）實際上沒有用功，也沒通過。

For things that didn't happen in the past: If I had studied harder, I would have passed the exam (but I didn't, and I didn't pass).

口語常縮寫：I'd have known、If I'd known。
Spoken short forms: I'd have known, If I'd known.

✗ If I knew you were coming, I would have cooked.
✓ If I had known you were coming, I would have cooked.
過去的假設，if 子句用 had ＋ p.p.。
Unreal past: had + p.p. in the if clause.
✗ If you had told me, I would help you.
✓ If you had told me, I would have helped you.
主要子句用 would have ＋ p.p.。
The main clause takes would have + p.p.

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

如果我們早點出門，就不會錯過火車了。

She could have won if she hadn't fallen.

如果她沒有跌倒，就可能贏了。

If I had known it was your birthday, I would have bought a gift.

如果我知道那天是你生日，就會買禮物了。

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。