有时可将条件从句的连词if省略,但此时应用倒装句型,即将从句中的were, should, had 等提到句首:
Were I Tom, I would refuse. 如果我是汤姆,我会拒绝。
I will go, should it be necessary. 假若有必要,我会去的。
Had it not been for the bad weather we would have arrived in time. 若不是天气坏,我们就准时到达了。
【注】
① 若条件从句为否定句,否定词not应置于主语之后,而不能与were, should, had 等缩略成Weren’t, Shouldn’t, Hadn’t而置于句首。
② 有时省略if后提前的had不是助动词:
Had I time, I would come. 假若我有时间,我会来的。(=If I had time…)
参考资料:http://baike.baidu.com/view/26751.htm