历年SAT真题中，名词单复数算是小众的考点了，在IE中的出现数量在0至2个之间徘徊。但正由于出现频率不高，考生对名词单复数的考察很容易忽略。因此对于名词单复数考查方式的总结剖析十分必要。根据06年到2012年的真题，所有IE,IS名词单复数的考点可以总结为以下四种形式：
1. 主系表/主谓宾结构中主语和表语/宾语数量不对等
首先我们要弄清主系表结构的含义。英文中主系表结构由主语，系动词和表语组成。主语为名词或者代词，位于句首。表语用来修饰主语，说明主语的身份、性质、品性、特征和状态，位于系动词之后。通常由名词、形容词、副词、介词短语、不定式、动词-ing或者从句来充当。例如：
He is at home. (at home是介词短语，作表语)
My favorite subject is reading. (reading是动名词，作表语)
系动词分为三类，
-Be动词
-表感官，如
Look, feel, seem, smell, taste, sound, touch
-表状态维持或转换，如
Turn, get, go, fall, remain, become, prove, appear, keep, stay, continue, stand
总而言之，系动词和表语联系十分紧密，有系动词就有表语，有表语就有系动词。在这一类考点中，形式多呈现为一个变多个或者多个变一个。
2009.10
(A significant factor )to include in the budget when (buying a car are the costs of fuel and maintenance and the( insurance payments.)
解析：每一道IE题，最重要的都是划分句子主干，先阅读句子的主干成分，即A factor are costs.很明显，这句话的主语是单数，而表语是复数，应把A改为Significant factors.
2010.1
A big vegetable salad is( generally )more nutritious (than )a low-fat pasta dish, (but )either meal would be (good choices) for the health-conscious eater.
解析：这句话主干是A salad is more nutritious than a dish, but either meal would be good choices. 问题在于后半句would be系动词连接的两部分数量不一致。
IS中也有同样的考点：
2009.5
Turquoise-inlaid frog and bird figurines( seems to have played an important role )in prehistoric ceremonies in what is now the southwestern United States.
(A) seems to have played an important role
(B) seems to have played important roles
(C) seems to be playing an important role
(D) seem to have played played important roles
(E) seeming to be playing important roles
解析：seems to have played是复合谓语，主语是复数，根据主谓一致必须用seem，且不可能是一个role，因此选D.
2011.1
Although Debussy and Ravel are generally considered( an impressionist composer, their compositional styles are) quite distinct from one another.
(A) an impressionist composer, their compositional styles are
(B) to be an impressionist composer, their compositional style is
(C) as having been impressionist composers, their compositional style is
(D) impressionist composers, their compositional styles are
(E) impressionist composers, whose compositional styles are
解析：Debussy和Ravel不能被看作一个人，排除A,B. 而C答案中style是单数，两个人的风格是styles;根据although的连词性质，后半部分必须有完整的句子，所以E的whose错。选D。
