托福考试辅导：语法讲解（33）

考点三 独立主格结构

独立主格结构是介于分词和主谓句之间的非谓语形式，对于分词来讲其逻辑主语必须和句子的主语保持一致，而独立主格则在很大程度上克服了这一局限性
1、主要特征
  (1) 独立主格是含有主语的分词结构，分词与主语间是主谓关系，
基本形式为：主语+现在分词或过去分词
如：his heart bleeding
   the baby crying
   the project completed
　　　    The school being over, the street was full of the students.
　　　     = When the school was over, the street was full of the students.

 (2)切记独立主格不等同于主谓结构，
比较：my mind wandering (独立主格)；
My mind was wandering (主谓结构)

  (3)独立主格的主语和句子主语不一致
如：(With) His mouth filled with water, he couldn't utter a word. (独立主格)
对于分词来讲其逻辑主语必须和句子的主语保持一致:
Filling his mouth with water, he couldn't utter a word.

2. 在句子中的作用
独立主格结构通常在句中表示时间、条件，原因、伴随状态等
如：The film being over, we had a stroll on the nearby street. (时间)
Weather permitting, I will go fishing with my family. (条件)
Time pressing, they had to work overtime. (原因)
The leaves rustling in the breeze, I roamed on the country road. (伴随)

例题：
(1)
   ----modern offices becoming more mechanized, designers are attempting to personalize them with warmer, less severe interiors.
  (A) If
  (B) But
  (C) With
  (D)Once

答案：C
解释：句中主干完整, 主语是designers, 谓语是are attempting, 之后是不定式构成的宾语. 空白后 becoming 采取分词形式, modern offices是becoming的逻辑主语, 因此可确定需填入的词会与原句构成独立主格结构, 而不是从句, A B D可一次性排除, 其实此句除去空白处, 已是完整的句子, 类似句子如: The man entered the room, his hair flying in the air.
注意: 表示伴随状态的独立主格结构通常可以由with引导, 如本例题.