倒装
固定语序
        主语+谓语

后置
1．句尾焦点和句尾重心
2．关键词语的后置
前置与倒装
1)不引起倒装的前置
不引起倒装的前置成分通常是宾语、主语补语和宾语补语。
2) 引起倒装的前置:
主语补语前置时，如主语较长或结构较复杂，就会引起倒装。
 前置宾语由not a + 名词或 not a single + 名词，就会引起倒装
A horrible mess I have made of it.
Books, I need.
Happy indeed I am
Happy indeed are those who got the tickets to Beijing.

倒装
某些状语的前置会引起倒装: 全部倒装和部分倒装  

a. 句首状语为方位词或拟声词，谓语动词为go, come等表示位置转移的动态动词时，通常用全部倒装，主语为代词，不用倒装。
Eg. Lower and lower he bent.

b. 当句首状语为表地点的介词词组时，也会引起全部倒装。
Eg. From the wall comes the voice of the doctor.

c. 当句首状语为否定词或带有否定意义的词语时，一般引起局部倒装。
Eg. Nowhere else could you find so cheap books.

d. 当句首状语为only + 副词, only +介词词组, only + 状语分句构成，也可引起局部倒装。
Eg. Only through sheer luck did he manage to get some tickets.  

e. 以关联连词so (…that)开头的句子，引起局部倒装。so+形容词是主语补语的前置；so+副词是状语的前置。
Eg. So small was the mark that I could hardly see it.

f. 当方式状语、频度状语等移至句首时，有时也引起局部倒装。也可不用倒装。
Eg.
Many a time has Mike given me good advice.
Slowly and impressively he rose from his seat.