英语的一个显著特征是它可轻易地把简单结构（一个中心意思）转化为复合结构（两个中心意思）和复杂结构（一个中心意思和一个从属意思）甚至转化为复合-复杂结构（两个或以上的意思）。主句，又称独立句，表达可独立成句的思想内容。从句，又称非独立句，表达不能独立成句，而需与主句一起构成完整的思想内容。

达到句式多变的最佳期途径是把关键词或短语换到开头或结尾，从中发现达到你的目的和适合你的品味的最好方法。通过连接短句--省词，增词，改变词序或把不那么重要的思想放到从句中去--你就可以写出更流畅，成熟的句子。

 

例 Before: Lu Hao graduated last summer. He joined the First Auto Works in Changchun soon after graduation. He received an engineering degree from his college.

采用从句能将这三个简单句以不同方式连接起来。

After:  After graduating last summer with an engineering degree, Lu Hao soon joined the First Auto Works in Changchun.

(介词结构 + 主语 + 谓语)

或：   An engineering degree-holder, Lu Hao joined the First Auto Works in hangchun last summer soon after graduation.

(同位语 + 主语 + 谓语 +状语)

或：   Having graduated with an engineering degree, Lu Hao joined the First Auto Works in Changchun last summer.

(状语+ 主语 + 谓语)