涉及虛擬倒裝的考題

_________ he followed my advice, he would have succeeded.

A. When                  B. If                         C. Had                     D. Has

答案應選C，但容易誤選B。不能選B，主要是因為時態前后有矛盾。由于主句謂語是would have succeeded，這表明是對過去事實作出的假設，所以從句謂語應該是 had followed，所以，如果選B，句子應該是 if he had followed my advice。但按英語語法，在此類表示虛擬條件的從句中，若有 had, should, were 等詞，便可省略 if，而將 had, should, were 提前置于句首。又如：

If he were my friend, I would ask him to lend me some money.= Were he my friend, I would ask him to lend me some money. 假若他是我的朋友，我就會向他借些錢。

If it should rain tomorrow, I should stay indoors.= Should it rain tomorrow, I should stay indoors. 如果明天下雨，我就呆在室內。

If he had asked me, I would have told him. = Had he asked me, I would have told him. 要是他問過我，我就會告訴他了。