爲了幫助大家更好地備考GMAT，下面yjbys網小編整理了關於GMAT語法中逗號怎麼用的問題，幫助各位瞭解如何正確做GMAT句子改錯題。
1. 前置修飾語的停頓形式化描述：M, S V O.
備註：M是修飾語，SVO是主謂賓，下同。其中該逗號可加可不加，看修飾語的長短。
例句1(加逗號) In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair because moisture exhaled by tourists had raised the humidity within them to such level that salt from the stone was crystallizing and fungus was growing on the walls.
例句2(不加逗號) In the 1960’s long-term studies of primate behavior often used as subjects tamaris.
2. 插入語形式化描述：S, ,V O.
備註：插在修飾對象和平行對象之間。
例句1 Plants are more efficient than fungi at acquiring carbon, in the form of carbon dioxide, and converting it to energy-rich sugars.
例句2 Diabetes, together with its serious complications, ranks as the nation’s third leading cause of death, surpassed only by heart disease and cancer.
3. 句尾的修飾語形式化描述：S V O, M.
備註：起到對前面句子或名詞的補充。
例句 gawa won the Nobel Prize for discovering how the body canconstantly change its genes to fashion a seemingly unlimited number of antibodies, each targeted specifically at an invading microbe or foreign substance.
4. 並列句或主從複合句子句之間的停頓形式化描述：S V, and S V.
備註：逗號並不是必須的'，看子句的長短。
例句1(加逗號) Although a surge in retail sales has raised hopes that a recovery is finally under way, many economists say that without a large amount of spending the recovery might not last.
例句2 (不加逗號) If one arm is lost it is quickly replaced.
5. 三者平行形式化描述：A, B, and C
備註：三者平行and前的逗號一般不省，如果省略也不算錯。
例句1 The report recommended that the hospital eliminate unneeded beds, consolidate expensive services, and use space in other hospitals.
例句2 Authoritative parents are more likely than permissive parents to have children who as adolescents are self-confident, high in self-esteem, and responsibly independent.
6. 特殊的兩者平行形式化描述：A, and B
備註：當A非常長的時候，有時候會出現兩者之間平行有逗號。
例句 Motion picture industry representatives said that there were about a million copies of Hollywood movies available online, and that they expected piracy to increaseas high-speed Internet connections became more widely available.
7. 遞進解釋形式化描述：S V O, M1, M2.
備註：M1修飾O，M2修飾M1裏面的名詞，形成遞進解釋關係。
例句 Construction of the Roman Colosseum began in A.D.69 and was completed a decade later, during the reign of Titus, who opened the Colosseum with a one-hundred-day cycle.
8. 省市在句中形式化描述：S 介詞C, P, V O.
備註：通常地名在解釋名詞，省市在句中，省後面也加逗號。
例句 The Glass House Mountains in Queensland, Australia, were sighted in 1770 by the English navigator Captain James Cook.
9. 兩個形容詞修飾名詞形式化描述：M, M N.
備註：英文中兩個形容詞可以用逗號隔開一起修飾名詞。
例句 In many cases they change direction toward the east before dissipating over the colder, more northerly waters or overland.
