一 语序：1、自然语序：主语+谓语+其它
2、倒装语序：部分倒装:1）助动词（be,do,have）+主语+谓语+其它.
全部倒装:2) 谓语动词+主语+其它.
二、倒装原因：
1、语法需要.
2、为了强调句子中的某个成分.
三、倒装结构的基本用法.
1、在疑问句中要部分倒装,谓语动词是be则完全倒装.
How long have you been in my army?
Are you a student?
2、在there be结构中要完全倒装.
There are about twenty students in the classroom.
３、在以here,there,out ,in,up,down,now .then等表示地点时间的副词放在句首时,要完全倒装,但主语是人称代词时,不能倒装.
4、only所修饰的副词,介词短语或状语放在句首时,要部分倒装.
Only in this way can you do it well.
5、含有否定意义的副词或连词,如：hardly,never,not ,not only,little,seldom等放在句首时,要部分倒装.
Little do I care about her past.
6、以so开头的句子,表示前面所说的情况也适用于后者,要部分倒装.其句型是：so+be/have/助动词或情态动词+主语.
You can drive a car.So can I .
You speake Chinese .So do I .
You are a student.So am I .
7、以neither ,nor开头的句子,表示前面否定的情况也适用于后者,要部分倒装.
You can't drive a car .Neither/nor can I .
8、以从属连词so```that/such```that中的so/such放在句首时,要部分倒装.
So loudly did the baby cry that I couldn't fall asleep.
Such a small sign was it that I could hardly see it .
9、直接引语的全部或部分放在句首时,要完全倒装,但当谓语比主语长,或谓语后面还有宾语时,则不要倒装.
"May I come in?"asked Fackson.
"Will you go with me "Tom asked Mary .
10、当句首状语用表示地点的介词短语来充当时,要完全倒装.
From the deep cave came a terrible cry .
11、当表示程度和方式的状语放在句首时可部分倒装,当主语较长时,可完全倒装.
Often did I see him swimming in the lake when I was a little girl.
With his words came a group of young man,who had guns in their hands.
12、当虚拟条件从句中"if"省去时,要部分倒装.
Had he seen you yesterday he would have asked about it .
13、某些让步状语从句（尤其是以as引出）可倒装谓语动词,表语,状语,部分倒装也可普遍.
Young as she was ,she could read lots of books.