在SAT語法中，邏輯主語問題是SAT語法部分的一個常見問題，對於句子修改題(Improving Sentences)而言更是如此。下面是小編爲大家整理收集的關於SAT語法常見形式與修改方法的相關介紹，希望對大家有所幫助。
一、常見形式
SAT語法中，邏輯主語問題的常見形式有下列幾種：
1. 句子以現在分詞開始
例如，
Lacking good instruction, my mistakes in creating a graph to illustrate historical trends were numerous. ( 句子以現在分詞lacking開始)
(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
2. 句子以過去分詞開始
例如，
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. (句子以過去分詞carried開始)
(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
3. 句子以介詞加動名詞開始
例如，
By simply entering an internet website or calling a toll-free number, a catalog order can be placedfor almost anything from cheesecakes to fully equipped desktop computers. (句子以介詞by加動名詞entering…or calling…開始)
(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
4. 句子以連詞加分詞或形容詞開始
例如，
While driving down the road, the house with the large yard and small pond attracted the family’s attention. (句子以連詞while加分詞driving down…開始)
(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
二、修改方法
從SAT語法上而言，如果句子開始是分詞結構，那麼它的邏輯主語必須是整個句子的主語。在修改句子題中，卻往往相反，即句子的主語不是分詞結構的邏輯主語。修改的方法是“一步必殺”法：將句子的主語替換爲分詞結構的邏輯主語(一般藏在句子中)。正確答案通常就是以分詞結構的邏輯主語爲句子主語的選項。根據“一步必殺”法，上述句子修改如下。
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
現在分詞lacking的邏輯主語，即整個句子的主語應該是“I”，而實際上卻是“my mistakes”。修改時只需要將句子的主語改爲“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)爲正確答案。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，因爲與原句相比，這麼做將使改後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. (句子以過去分詞carried開始)
(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該是“dust”(dust 被winds吹走)，而實際上卻是“eruption”。修改時只需要將句子的主語改爲“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之後的crossed成了that引導的從句的謂語，也使得整個句子沒有謂語，因此(D)爲干擾選項， (C)爲正確答案。
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. (句子以介詞by加動名詞entering…or calling…開始)
(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之後的動名詞entering與calling的邏輯主語，即整個句子的主語應該是人，例如you、one等，而實際上卻是“a catalog order”。修改時只需要將句子的主語改爲人就可以了。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無法協調) ，因此(C)爲干擾選項， (D)爲正確答案。
4. While driving down the road, the house with the large yard and small pond attracted the family’s attention. (句子以連詞while加分詞driving down…開始)
(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之後的現在分詞driving down的邏輯主語，即整個句子的主語應該是人，也就是句中的family，而實際上卻是“the house”。修改時只需要將句子的主語改爲family就可以了。符合這個要求的只有(E)選項，因此 (E)爲正確答案。(D)選項的主語是attention，而不是family，因此是干擾選項。