相信各位小伙伴们在sat阅读中，能大量地看到"独立主格结构"这种语法现象。而要理解含有这类语法现象的句子，需要中国学生对于动词以及其逻辑主语有清晰的认识，一起来看看sat语法中独立主格的用法!
(1)在形式上，独立主格结构由两部分组成：第一部分由名词或代词担任，第二部分由分词、动词不定式、形容词、副词或介词短语担任。
(2)按其结构形式分为：-lng分词独立主格结构;-ed分词独立主格结构;无动词独立主格结构(常常省略了being);with/without引导的独立主格结构等。
我们来看一个例子：
Inside. we sat on wonderfully comfortable seats that were tilted back so that you lay in a sort of a hammock. attention directed to the bowl of the ceiling,which soon turned dark blue which sOOn tumed da rk blue. with a faint rim of light around the edge.
【译文】在里面，我们坐在非常舒服的位子上，座位向后靠，就像躺在吊床里一样。视线转移到了天花板的吊顶上，吊顶很快变成了深蓝色，边缘还留着微弱的光圈。
【解释】难点一：在seats后是一个由that引导的定语从句，修饰seats;难点二：that引导的定语从句中有一个由so that引导的状语从句;难点三：attention directed to the bowl of the ceiling这是一个独立主格结构。逻辑主语为attention. directed to过去分词结构，与attention呈现出被动关系。这里就是一个典型的-ed分词独立主格结构。with a faint rim of light around the edge又是一点由with引导的独立主格结构：with+名词+介词短语。
再来看一个例子：
Habituated by my own geological training and knowledge,1 was not quite prepared upon opening this New Atlas of the Universe to encounter the faces of so many worlds, dangling in the black of space, their features available to the eye for instant interpretation.
【译文】局限于我自身的地质学知识，我还没准备好翻开这本《宇宙图鉴》去探索这些悬挂在宇宙中的新天地，尽管它们的特征是一目了然。
【解释】难点-：habituated by my own geological training and knowledge在这里是过去分词做状语;难点二：dangling in the black of space这是一个现在分词做定语用来修饰the faces of so many worlds;难点三：their features available to the eye for instant interpre-tation这里是一个独立主格结构，逻辑主语为their features与available构成逻辑关系，省略了being.这是一个典型的无动词独立主格。