談到GMAT考試，很多考生可能對verbal部分的語法(sentence correction)環節表示很糾結：對於中學所學語法知識的遺忘、做題正確率的低下、題意晦澀選項太長導致做題速度過慢……各種各樣問題使得考生視SC為大敵，久久找不到突破點。其實，靜下心來詳細分析GMAT考試的目的與本質，想一想美國人通過GMAT到底要考大傢什麼，我們將會發現SC環節中的規律性。小編將在這篇文章中帶領大家從sentence correction環節找尋其考點規律。
國內，很多考生將sentence correction環節定義為語法，而小編認為這一定義並不確切，因為SC題目中除了對語法進行考核之外，還會對標準書面英語，也就是所謂的文法有所要求。接下來，小編將從語法和文法兩個角度分析該環節的考核規律。
1)語法的準確性
一般來說，GMAT SC環節對於語法知識的考核會從主謂一致(agreement), 比較結構(comparison), 平行結構(parallelism), 代詞指代(pronoun), 動詞(verb), 以及修飾(modifier)等等幾大語法點對大家進行考察，這也就要求大家在對該環節進行準備前，首先應當對所學過的語法概念做出系統性鞏固，從上述若干考點查漏補缺，鞏固語法基本功。但是值得注意的是，由於GMAT對於語言的考核是立足於formal written standard English, 所以大家在準備時，還應特別留意一些GMAT做出的特殊要求。下列若干句子在傳統語法書甚至國內中大學聯考等大型考試都被認為是正確的句子，但從GMAT要求來分析是存在語法錯誤的。例如：
will come to attend the conference, which is a good news for us.
國內較為權威的語法書籍例如張道真語法和薄冰語法對於非限定性定語從句中關係代詞which既可用來指代前面整句也可以具體指代句中某一成分。而從GMAT角度分析為避免理解歧義，which只能指代句中某一成分，而不能指代整句;因此，在該例句中，which用來指代”he will come to attend the conference”, 該句錯誤。
因此：在下列這道題目中，我們可以根據該原則排除掉ACE三個選項，因為從ACE三選項中的謂語動詞單三形式doubles可以得知關係代詞which在該題中指代 “The cameras of the spacecraft detected six small, previously unseen moons circling Uranus” 這一整句話，這就為我們做題無論從速度和正確率上會有很大提高作用。
The cameras of the spacecraft detected six small, previously unseen moons circling Uranus, which doubles to twelve the number of satellites now known as orbiting the distant planet.
A which doubles to twelve the number of satellites now known as orbiting
B doubling to twelve the number of satellites now known to orbit
C which doubles to twelve the number of satellites now known in orbit around
D doubling to twelve the number of satellites now known as orbiting
E which doubles to twelve the number of satellites now known that orbit
b. He said he wanted to go home.
傳統語法規定，賓從連線連詞that一般情況下均可省略，但是GMAT考試明確，名詞性從句連線連詞不得省略。
因此：在下面這道題目中，B選項由於謂動order後直接接了賓從而缺失了連線連詞that，可以排除掉該選項
The newly passed bills order that the state tax revenue be cut each year.
A. order that the state tax revenue be cut
B. order the state tax revenue be cut
C. order that the state tax revenue will be cut
D. have an order for a cut state revenue
E. have an order to cut the state revenue
類似這樣的GMAT特有語法規定還有很多，例如this不得單獨使用，虛擬語氣名詞性從句中謂動不得加should等等，這些看似條條框框的規定實際上更多的為我們提供的是一種規律，也就是說在眾多選項中，總有那麼幾個標誌性的規律性的詞眼在幫助我們排除若干選項。所以，對於語法知識的掌握，既要立足於鞏固語法基本功，又要系統性的總結GMAT特有規定。
但是，大家在實際操作時可能往往會發現，當利用選項中的語法錯誤排除之後往往會有兩三個選項貌似沒有任何語法問題，那麼這個時候怎麼辦呢?小編接下來將淺談該環節對於文法的`考察。
2)文法的有效性
“有效性”實際上是一個比較寬泛的概念，GMAT SC秉行一句格言 “沒有完美的，只有更好的”。在抓住語法錯誤進行排除之後，有時往往會留下兩個左右語法看似完全正確的句子，這時我們就需要分析剩下選項中哪一個表達意思和原題意思最貼切，哪個選項表達更加簡潔，以及哪個選項中邏輯最為清晰;總之在有效性的基礎上進行選擇。
例如
Last spring a Colorado health department survey of 72 playgrounds in private child-care centers found unsafe conditions in 95 percent of them and they ranged from splinters to equipment near collapse.
A. unsafe conditions in 95 percent of them and they ranged
B. conditions in 95 percent were unsafe and ranging
C. the ranging of unsafe conditions in 95 percent of them to be
D. that 95 percent had unsafe conditions ranging
E. that 95 percent had conditions that were unsafe; the range was
在該題目當中的D和E兩個選項中，由於D中的 “unsafe conditions” 表達上等同於E選項中 “conditions that were unsafe”, 以及D中的 “ranging”分詞做定語修飾 conditions簡潔於E中分號隔開的並列句，所以在DE語法正確的情況下我們優先選擇D選項。
再例如：
As the price of gasoline rises, which makes substituting alcohol distilled from cereal grain attractive, the prices of bread and livestock feed are sure to increase.
A. which makes substituting alcohol distilled from cereal grain attractive
B. which makes substituting the distillation of alcohol from cereal grain attractive
C. which makes distilling alcohol from cereal grain an attractive substitute
D. making an attractive substitution of alcohol distilled from cereal grain
E. making alcohol distilled from cereal grain an attractive substitute
在該題目中，利用之前講過的which不得指代前面整句排除掉ABC三個選項的之後，我們對比DE兩個選項，我們不難發現D中表達的結構是making substitution distilled (make something done/使某事被做)，不但表達意思和原題意思區別較大，而且混淆了名詞“substitute” 和 “substitution”間的區別，所以我們可以直接排除D而選擇E選項
