第九章悬垂结构.doc

第九章悬垂结构 第一节悬垂结构语法知识 所谓悬垂结构，是指现在分词( V-ing)或过去分词(V-ed)在句子中作状语时，其逻辑主语（即该动作的发出者）从文法的要求来看，必须是句子的主语，但如果该主语和现在分词或过去分词在逻辑上又没有联系，那么现在分词或过去分词就变成了一个没有依附的分词，文法上称这样的错误情况叫悬垂结构。 悬垂结构是SAT重点考查的内容。通过认识悬垂结构，可以帮助我们迅速排除一些错误选项。 例：After reading the book,一． (A)I fed the dog (B) the dog was fed by me (C) feeding the dog was his task (D) the dog was hungry 如果reading the book作状语，作主语的成分就必须是reading the book的动作发出者。在各选项中，只有A符合条件，而其他选项的主语均不能作为reading the book的动作发出者，故正确选项为A。 当句子以V-ing开头，则句子的主语必须是该动作的发出者；当句子以V-ed 开头，则主句必须和该V-ed构成被动关系。当我们看到一个句子以V-ing或V-ed 开头时（有时前面有after、before、while或when之类的连词），首先要考虑句子主语必须和V-ing或V-ed在逻辑上有关系，凡是没有关系的必定是错误选项。 例：(A) Writing in a free style, the novelist is popular among the children (B) Written in a free style, the novel is popular among the children 在A句中，write的动作是由主语the novelist发出的，故采用V-ing形式； 在B句中，the novel是被写的，故采用V-ed形式。  为进一步了解悬垂结构，我们来分析下列例句的正误： (A) Waitine for a bus,a brick fell on my head (B) Driving on the road that night,a squirrel suddenly leapt out of the jungle. (C) Getting down from the bus, my ankle was sprainecL (D) Looking out of the window, there were many people on the streets. (E) Sitting under an apple tree one night,a new idea came to Newton (F) Looking in this way,the situation didnt seem that bad (G) WritinS in a free style, the novelist is popular. (H) Ranked as one of the top ten university, many students are eager to have the chance to study in Princeton 【分析】 (A)错。因为brick不能发出writing这样的动作。该句为典型的悬垂结构。应改为： WaitinS for a bus,1 was hit by a brick (B)错。因为a squirrel不能发出driving这样的动作。应改为： DrivirX; on the road that night,Tom saw a squirrel leaping out of the jungle. (c)错。发出getting down from the bus动作的是句子主语my ankle，而这从逻辑上是讲不通的。应改为： Getting down from the bus,I got my ankle sprained (D)错。发出looking out of the window这个动作的行为主体应是句子的主语。可改为： LookinS out of the window,Mary saw many people on the street (E)错。是Newton发出sitting under an apple tree这个动作，故