SC迷思:「邏輯主詞」(Logical Subject)等於「主詞」嗎?

很多高分區的考點,其實OG都有出現過,只是你不知道如何判斷。
其中一個,就是大家天天掛在嘴邊,耳熟能詳的「邏輯主詞」(Logical Subject)。

「邏輯主詞」一提到這個名詞,大家都會覺得「阿不就是主詞嗎?」
但仔細想想,如果Logical Subject真的等於Subject,
那幹嘛還要特別強調「邏輯」?



所以邏輯主詞跟文法上的主詞不一定相同。
之所以叫「邏輯」主詞,因為他表達的是「句意上」該找誰當這個動作的主詞。

什麼時候需要找邏輯主詞呢?

句子核心S+V中的V需要找嗎?不用。
他的主詞已經在句子中固定了。
所以真正需要找主詞的,其實是「修飾語」。

哪些修飾語需要找邏輯主詞?

形容詞子句(which/that...)需要嗎?不需要。
因為which跟that已有明確的指代對象。

真正需要的是動作化成的修飾語,也就是分詞結構跟不定詞結構:
1. Ving/Vpp...
2. to V

怎麼找?
邏輯主詞的「邏輯」指的是「句意」,所以一定不能逃避看句意。
牢記一個原則:
「修飾對象會跟修飾語共用一個動作發出者」。

實際練習:

Among lower-paid workers, union members are less likely than nonunion members to be enrolled in lower-end insurance plans imposing stricter limits on medical services and requiring doctors to see more patients, and spend less time with each.

正確選項:
(D) that impose stricter limits on medical services and require doctors to see more patients, spending
這裡的, spending less time with each在句意上是see more patients的後果,所以修飾對象是 see這個動作,要跟see共用動作發出者doctor,而不是去找前面的文法lower-end insurance plans主詞。

Australian embryologists have found evidence that suggests that the elephant is descended from an aquatic animal, and its trunk originally evolving as a kind of snorkel.
(B) that has suggested the elephant descended from an aquatic animal, its trunk originally evolving 

(E) to suggest that the elephant is descended from an aquatic animal and that its trunk originally evolved

B選項的has suggested主詞是that代替的evidence。
E選項的to suggest表目的,修飾最接近的動作(手段)found,跟其共用動作發出者Australian embryologists。

誰比較適合做suggest一個結論的動作?當然是人。所以答案是E。

Researchers are using computer images to help surgeons plan difficult operations and to develop programs that will work for doctors and nurses in the same way that flight simulators do for pilots, letting medical personnel practice their techniques and test their reflexes before they ever see a patient.

(A) plan difficult operations and to develop programs that will work for doctors and nurses in the same way that flight simulators do
(B) plan difficult operations and develop programs to work for doctors and nurses the same way as with flight simulators
(C) to plan difficult operations and to develop programs that will work for doctors and nurses like flight simulators 

A選項的 to develop跟to help平行,to help又是表目的,修飾最接近的動作(手段)are using,跟are using共用一個動作發出者Researchers。所以to develop的邏輯主詞是Researchers。
B選項的develop與plan平行,plan作為help surgeons plan...的一部份,句意上的動作發出者為surgeons,所以develop的邏輯主詞是Surgeons。
C選項的to develop跟to plan平行,to plan是help surgeons to plan的一部份,句意上的動作發出者為surgeons,所以to develop的邏輯主詞是Surgeons。

所以,到底是醫生還是學者會寫程式?當然是學者。答案為A。

除此之外,B選項還有一個問題:to work。

to work單獨出現表目的,修飾最接近的動作(手段)develop,develop跟plan平行,plan作為help surgeons plan...的一部份,句意上的動作發出者為surgeons,所以to work的邏輯主詞是Surgeons。

醫生幫助醫生合理嗎?應該是程式幫助醫生才合理吧。

最後是這一題:

New items developed for automobiles in the 1997 model year included a safer air bag , which, unlike previous air bags, eliminated the possibility that a burst of smoke would appear when the bag inflated, and making an already terrified passenger think the car was on fire.

(D) Inflated and make
(E) Inflated to make

D選項and make與appear平行,主詞為a burst of smoke。
E選項to make單獨出現表目的,修飾最接近的動作(手段)inflated,共用同個動作發出者the bag。

是a burst of smoke讓人們認為車子著火?還是the bag讓人們認為車子找火?

以上,希望能帶給大家一個完整而正確的觀念。
邏輯主詞不一定是主詞,而是「句意上修飾對象」的動作發出者。