在英语中，主语和谓语是句子的核心，它们之间有两种语序：一是主语在谓语之前称为自然语序(Natural Order);二是主语在谓语之后则称为倒装语序(Inverted Order)。而倒装语序中又有完全倒装(Full Inversion)和部分倒装(Partial Inversion)
1.完全倒装(Full Inversion)：又称"全部倒装",是指将句子中的谓语全部置于主语之前。此结构通常只用于一般现在时和一般过去时。
①谓语+主语+……
There be(的各种形式)+主语(+地点或时间状语)
例子：
There was a drop in the temperature.
There are birds singing in the tree.
③过去分词或现在分词+be动词的各种形式+主语+……
例子：
Scattered on the floor were several books and magazines.
2.部分倒装(Partial Inversion)(又称半倒装句)：指将谓语的一部分如助动词或情态动词倒装至主语之前,而谓语动词无变化。如果句中的谓语没有助动词或情态动词，则需添加助动词do,does或did，并将其置于主语之前。
例如：
Nor did he let the disease stop him from living the kind of life he has always dreamt about.
1. 以否定词开头的句子要求部分倒装。注意下列句子中助动词或情态动词提前、甚至补充助动词的用法：
例：
Not until yesterday did little John change his mind.
2.以否定副词开头并加状语放在句首的句子要求部分倒装。这些否定副词有barely, hardly, little, seldom, scarcely…… when, never, no sooner…… than, rarely, no more, not nearly, not only等以及only。
例：
Only in the country can you learn the "true English".
3.介词+no+名词的结构中需要用部分倒装，这些结构包括at no time; by no means; by no manner of means; for no reason; in no case; in/under no circumstances; in no sense; in no way; on no account; on no consideration; at no point
例：
Under no circumstances should you lend Paul any money.
4. 由as引导的部分倒装句：
a) 当as作为比较意义时，即用于as + adj./ adv. + as结构中时，如果把第一个as省略掉，就形成部分倒装句。
例：
Cautious as the rest of her family (was) , she didn't seem willing to give an immediate reply to my question.
正如她家里人一样谨慎小心，她似乎不愿意立即回答我的问题。
She charged the stairs, quick as a rabbit (ran).
b) 当 as引导让步状语时，和although, though一样，当用作"尽管"之义时，可以用于部分倒装句。
Hard as he worked, he did not pass the exam.
例：
Tired as he was, we decided not to disturb him.
例：
She worked hard, so/ as did her husband.
