1 虚拟语气倒装 当虚拟条件句中含有 were，had，should，could等动词时，可以将if省略，然后将 were，had，should，could 等词移至句首： 1）If he should fail，he would kill himself. →Should he fail，he would kill himself. 万一失败，他就会自杀。 2）If I were you，I would do it at once. →Were I you，I would do it at once. 假若我是你，我就会马上做。 3）If I could do it，I would. →Could I do it，I would. 要是我能做此事，我一定会做。 4）If he had seen you yesterday，he would have asked you about it. →Had he seen you yesterday，he would have asked you about it. 他昨天要是看到了你，他就会问你这事了。 再看一些例句： 1）Were they here now, they could help us. =If they were here now, they could help us. 他们现在在的话，就会帮助我们了。 2）Had you come earlier, you would have met him. =If you had come earlier, you would have met him. 你来得早一点，就碰到他了。 3）Should it rain, the crops would be saved. =Were it to rain, the crops would be saved. 假如下雨，庄稼就有救了。 4）Were I（= If I were）in your place，I wouldn’t do it． 5）Had you（= If you had）seen it，you would have believed． 6）Were they to get married（= If they were to get married），the would not be happy． 7）Should he come，tell him to ring me up. 他要是来了，让他给我打个电话。 8）Were I in your position，I would go. 如果我处于你的地位，我就去。 9）Had they not helped us，our experiment would have failed. 如果没有他们的帮助，我们的试验是会失败的。 典型例题： 1）Not until the early years of the 19th century___ what heat is A. man did know B. man knew C. didn\'t man know D. did man know 1 答案为D. 否定词Not在句首，要求用部分倒装的句子结构。 2）Not until I began to work ___ how much time I had wasted. A. didn\'t I realize B. did I realize C. I didn\'t realize D. I realize 答案为B。 3） Do you know Tom bought a new car? I don\'t know, ___. A. nor don\'t I care B. nor do I care C. I don\'t care neither D. I don\'t care also 答案为B. 句中的nor引出部分倒装结构，表示\"也不\"。由 so, neither, nor引导的倒装句，表示前一情况的重复出现。其中, so用于肯定句, 而 neither, nor 用在否定句中。 4）_____ to do the work, I should do it some other day. A. If were I B. I were C. Were I D. Was I 答案C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说 Were I not to do, 而不能说 Weren't I to do。 5）__________ your address，I would have written to you. A. Did I know B. Were I to know C. Had I known D. If I should know 此题应选 C。这是虚拟语气的倒装形式。 本文来源：https://www.wddqw.com/doc/a0c60e38571252d380eb6294dd88d0d233d43cd0.html