1.当虚拟条件句的谓语部分含有were, should, had时，我们可以将连词if省略掉，而将were, should, had置于句首。
2.对于条件从句含有should而主句使用陈述语气或祈使语气的句子也可以采用以上方法进行省略和倒装。有时被提到句首的had不是助动词，而是表示“有”的实义动词。
3. 如果条件从句为否定式，注意要将not置于主语之后，而不置于主语之前。
4. 在这类倒装结构中，置于句首的were习惯上不能用was代替。
倒装句用法解析
一、 表示强调:
倒装句最突出、最常见的修辞效果就是强调,其表现形式如下:
1. only +状语或状语从句置于句首,句子用部分倒装。
eg.Only in this way can you solve this problem. 只有用这种方法,你才可以解决这个问题。
eg.Only after he had spoken out the word did he realize he had made a big mistake.只有当他已经说出那个字后才意识到自己犯了个大错误。
2. not, little, hardly, scarcely, no more, no longer, in no way, never, seldom, not only, no sooner等具有否定意义的词或词组位于句首,句子用部分倒装。
eg. No sooner had I got home than it beg.an to rain. 我刚到家就下起了雨。
eg. Seldom do I go to work by bus. 我很少乘公共汽车上班。
二、 承上启下
有时倒装可把前一句说到的人或物,或与前一句有联系的人或物在下一句紧接着先说出来,从而使前后两句在意思上的关系更加清楚,衔接更加紧密,起到承上启下的作用。
eg.They broke into her uncle's bedroom and found the man lying on the floor, dead. Around his head was a brown snake. 他们破门进入她叔叔的卧室,发现他躺在地板上死了。一条棕褐色的蛇缠在他头上。
eg. We really should not resent being called paupers. Paupers we are, and paupers we shall remain. 我们确实不应因为被称作穷光蛋而愤愤不平。我们的确是穷光蛋,而且还会继续是穷光蛋。
三、 制造悬念,渲染气氛
在新闻或文学创作中,有时为了内容的需要,或是为了强调,作者常常运用倒装来制造悬念,渲染气氛。如:
Hanging on the wall was a splendid painting. 墙上挂着一幅精美的图画。
四、 平衡结构
英语修辞的一个重要原则是尾重原则,即把句子最复杂的成分放在句尾以保持句子平衡。在语言使用中为了避免产生头重脚轻、结构不平衡的句子,我们常采用倒装语序。
If she were in charge, she would do things differently.=Were she in charge, she would do things differently. 如果是她负责，她会是另一种做法。
If you should change your mind, no one would blame you.=Should you change your mind, no one would blame you. 万一你改变主意，谁也不会怨你。
If the management had acted sooner, the strike wouldn’t have happened.= Had the management acted sooner, the strike wouldn’t have happened. 如果资方早些采取行动，就不会发生罢工了。
几点说明：
1. 对于条件从句含有should而主句使用陈述语气或祈使语气的句子也可以采用以上方法进行省略和倒装。如：
If I should be free tomorrow, I will come. = Should I be free tomorrow, I will come. 如果明天我有空我就来。
If they should attack us, we’ll wipe them out completely.=Should they attack us, we’ll wipe them out completely. 假如他们进攻我们，我们就把他们彻底消灭干净。
有时被提到句首的had不是助动词，而是表示“有”的实义动词。如：
Had I the time, I would go. 如有时间我就去。
2. 如果条件从句为否定式，注意要将not置于主语之后，而不置于主语之前。如：
若非你的帮助，我仍会无家可归。
误：Weren’t it for your help, I would still be homeless.
正：Were it not for your help, I would still be homeless.
要不是我亲眼所见，我都不会相信了。
误：Hadn’t I seen it with my own eyes, I would not have believed it.
正：Had I not seen it with my own eyes, I would not have believed it.
3. 在这类倒装结构中，置于句首的were习惯上不能用was代替。如：
如果我是在你的立场，我不愿意做那件事。
If I were in your place, I wouldn’t do that.
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