SAT語法題目中的常見錯誤類型是邏輯主語錯誤，即句子的主語不是分詞結(jié)構(gòu)的邏輯主語。修改這種錯誤的方法很簡單，只要用隱藏在句子中的邏輯主語替換掉句子原來的主語即可。我們通過以下四道例題來具體講解這種方法：
1. Lacking good instruction, my mistakes in creating a graph to illustrate historical trends were numerous.
(A) my mistakes in creating a graph to illustrate historical trends were numerous
(B) I made numerous mistakes in creating a graph to illustrate historical trends
(C) there were numerous mistakes in the graph I created to illustrate historical trends
(D) I created a graph to illustrate historical trends with numerous mistakes
(E) The graph I made for illustrating historical trends had numerous mistakes
現(xiàn)在分詞lacking的邏輯主語，即整個句子的主語應(yīng)該是I，而原句中卻是my mistakes。修改時只需要將句子的主語改為I就可以了。符合這個要求的有(B)與(D)兩個選項，其中(D)選項將numerous mistakes放錯了位置，使得整個句子意思荒謬。因此(B)為正確答案。這也告訴考生，正確答案只要改正原句的主要錯誤就可以了，而無須做太多額外的修改，否則將使改后的句子變得面目全非。
2. Carried by the strong, dry winds of the stratosphere, the 1980 eruption of Mount Saint Helens caused dust that crossed the United States in three days and circled the globe in two weeks.
(A) the 1980 eruption of Mount Saint Helens caused dust that
(B) Mount Saint Helens' eruption in 1980 caused dust that
(C) dust from the 1980 eruption of Mount Saint Helens
(D) dust from the 1980 eruption of Mount Saint Helens that
(E) there was dust from the 1980 eruption of Mount Saint Helens and it
過去分詞carried的邏輯主語，即整個句子的主語應(yīng)該是dust(dust 被winds吹走)，而原句卻是eruption。修改時只需要將句子的主語改為dust就可以了。符合這個要求的有(C)與(D)兩個選項，其中(D)選項保留了原句的that，使得that之后的crossed成為that引導(dǎo)的從句的謂語，也使得整個句子沒有謂語，因此(D)為干擾選項，(C)為正確答案。
3. By simply entering an internet website or calling a toll-free number, a catalog order can be placed for almost anything from cheesecakes to fully equipped desktop computers.
(A) a catalog order can be placed
(B) by placing a catalog order
(C) they will place your catalog order
(D) you can place a catalog order
(E) your catalog order can be placed
介詞by之后的現(xiàn)在分詞entering與calling的邏輯主語，即整個句子的主語應(yīng)該是人，例如you, one等，而原句中卻是a catalog order。修改時只需要將句子的主語改為人就可以了。符合這個要求的有(C)與(D)兩個選項，其中(C)選項存在代詞混用的情況(they與your無法協(xié)調(diào))，因此(C)為干擾選項，(D)為正確答案。
4. While driving down the road, the house with the large yard and small pond attracted the family’s attention.
(A) the house with the large yard and small pond attracted the family’s attention
(B) the house having the large yard and a small pond attracted the attention of the family
(C) the house with the yard and small pond was attractive to the family’s attention
(D) the family’s attention was attracted by the house with the large yard and small pond
(E) the family was attracted to the house with the large yard and small pond
連詞while之后的現(xiàn)在分詞driving down的邏輯主語，即整個句子的主語應(yīng)該是人，也就是句中的family，而原句中卻是the house。修改時只需要將句子的主語改為family就可以了。符合這個要求的只有(E)選項，因此 (E)為正確答案。(D)選項的主語是attention，而不是family，因此是干擾選項 。
由此可見，SAT語法部分的錯誤通常都是有規(guī)律可循的。只要能迅速將錯誤歸類，并了解此類錯誤的一般改正方法，大多數(shù)SAT語法改錯題就迎刃而解了。
