1. 省略 if —— 何秀華
凡表假設語氣的 if 子句中, 若有過去完成式助動詞 had,或表『萬一』的助動詞 should,或有 were 出現時,可將 had、should、were(何秀華)置主詞前,而將 if 省略。
had: If I had known it, I would have told John.
= Had I known it, I would have told John.
(如果我早知道的話,就會告訴約翰了。)should: If John should do it, I would punish him.
= Should John do it, I would punish him.
(萬一約翰做了這件事,我就會處罰他。)were: If I were you, I wouldn't do it.
= Were I you, I wouldn't do it.
(如果我是你,就不會做這件事。)
2. 時態不一致的假設
也就是 if 子句與過去事實相反,使用過去完成式;主要子句與現在事實相反,使用過去式助動詞。句型如下:
If + 主詞 + had + 過去分詞,主詞 + |
would could might should ought to |
+ 原形動詞 + now / today |
例: If I had met Jane five years ago, she might have been my wife now. (×)
→ If I had met Jane five years ago, she might be my wife now. (○)
(我若是在五年前認識珍的話,她現在可能就是我太太了。)