【问】 Had he been more careful，he would not have made any spelling mistakes.划线部分是什么意思?

【答】 Had he been=If he had been。由于had提到主语之前，故省去了连词if。这种从句可以称做无连词条件从句(见should，were)：

1. Had you not helped me，I should have failed.

如果没有你的帮助，我就失败了。

2. Had I known，I would have written before.

如果我知道，我以前就写信了。

3. Had I not seen it with my own eyes，I would not have believed it.

如果不是亲眼看到了，我是不会相信的。

4.O had he only been here! =O if only he had been here!

噢，要是他在这里就好了!

5. Had Mark been in charge，it wouldn’t have happened.

如果马克主管，这事就不会发生了。

6. Had it not been for his skill，he would have fallen a prey to the wolves.

如果他没有绝技，他早就被狼群捕食了。

请注意not在从句中的位置：只能放在实义动词之前。

请做下面的英语试题：

“The taxi only took ten minutes to get to the hotel.”“____you were coming today.I’dhave met you at the airport.”

A. Have I known B. I have known

C. Had I known D. I had known(TOEFL，73.6，75.5)

(参见 conditional clause without a conjunction，were³)