SAT语法中常见的逻辑主语问题

SAT语法中常见的逻辑主语问题逻辑主语问题是SAT语法部分的一个常见问题，对于句子修改题(ImprovingSentences)而言更是如此。为了帮助SAT考生迅速理解这个问题并掌握解决办法，本文拟从它的常见形式与修改方法两个方面进行阐述。一、常见形式逻辑主语问题的常见形式有下列几种：1.句子以现在分词开始例如，Lackinggoodinstruction,mymistakesincreatingagraphtoillustratehistoricaltrendswerenumerous.(句子以现在分词lacking开始)(A)mymistakesincreatingagraphtoillustratehistoricaltrendswerenumerous(B)Imadenumerousmistakesincreatingagraphtoillustratehistoricaltrends(C)therewerenumerousmistakesinthegraphIcreatedtoillustratehistoricaltrends(D)Icreatedagraphtoillustratehistoricaltrendswithnumerousmistakes(E)ThegraphImadeforillustratinghistoricaltrendshadnumerousmistakes2.句子以过去分词开始例如，Carriedbythestrong,drywindsofthestratosphere,the1980eruptionofMountSaintHelenscauseddustthatcrossedtheUnitedStatesinthreedaysandcircledtheglobeintwoweeks.(句子以过去分词carried开始)(A)the1980eruptionofMountSaintHelenscauseddustthat(B)MountSaintHelens’eruptionin1980causeddustthat(C)dustfromthe1980eruptionofMountSaintHelens(D)dustfromthe1980eruptionofMountSaintHelensthat(E)therewasdustfromthe1980eruptionofMountSaintHelensandit3.句子以介词加分词开始例如，Bysimplyenteringaninternetwebsiteorcallingatoll-freenumber,acatalogordercanbeplacedforalmostanythingfromcheesecakestofullyequippeddesktopcomputers.(句子以介词by加分词entering…orcalling…开始)(A)acatalogordercanbeplaced(B)byplacingacatalogorder(C)theywillplaceyourcatalogorder(D)youcanplaceacatalogorder(E)yourcatalogordercanbeplaced4.句子以连词加分词或形容词开始例如，Whiledrivingdowntheroad,thehousewiththelargeyardandsmallpondattractedthefamily’sattention.(句子以连词while加分词drivingdown…开始)(A)thehousewiththelargeyardandsmallpondattractedthefamily’sattention(B)thehousehavingthelargeyardandasmallpondattractedtheattentionofthefamily(C)thehousewiththeyardandsmallpondwasattractivetothefamily’sattention(D)thefamily’sattentionwasattractedbythehousewiththelargeyardandsmallpond(E)thefamilywasattractedtothehousewiththelargeyardandsmallpond二、修改方法从语法上而言，如果句子开始是分词结构，那么它的逻辑主语必须是整个句子的主语。在修改句子题中，却往往相反，即句子的主语不是分词结构的逻辑主语。修改的方法是“一步必杀”法：将句子的主语替换为分词结构的逻辑主语(一般藏在句子中)。正确答案通常就是以分词结构的逻辑主语为句子主语的选项。根据“一步必杀”法，上述句子修改如下。1.Lackinggoodinstruction,mymistakesincreatingagraphtoillustratehistoricaltrendswerenumerous.(A)mymistakesincreatingagraphtoillustratehistoricaltrendswerenumerous(B)Imadenumerousmistakesincreatingagraphtoillustratehistoricaltrends(C)therewerenumerousmistakesinthegraphIcreatedtoillustratehistoricaltrends(D)Icreatedagraphtoillustratehistoricaltrendswithnumerousmistakes(E)ThegraphImadeforillustratinghistoricaltrendshadnumerousmistakes现在分词lacking的逻辑主语，即整个句子的主语应该是“I”，而实际上却是“mymistakes”。修改时只需要将句子的主语改为“I”就可以了。符合这个要求的有(B)与(D)两个选项，其中(D)选项将numerousmistakes放错了位置，使得整个句子意思荒谬。因此(B)为正确答案。这也告诉考生，正确答案只要改正原句的主要错误就可以了，而无须做太多额外的修改，因为与原句相比，这么做将使改后的句子变得面目全非。以上是为考生们介绍的SAT语法中常见的逻辑主语问题，希望对正在备考SAT的考生们有帮助。