GMAT语法题，又称句子改错题(sentence correction)，是整个GMAT考试中对考生英语语法能力考查要求最高的题型，也往往是中国学生最为头疼的一类题目。没有扎实的语法基础和一定的逻辑分析能力，想要做好语法题难度极高。怎样做好GMAT语法题?下面小编就通过一些经典真题的实例解析，为大家全面讲解GMAT语法题的解题思路和方法技巧。
实例题目：
Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.
(A) Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are
(B) Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(C) Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
(D) Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood,
(E) Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood,
选项分析：
(A)Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are
【正确】 “having amassed a wealth of knowledge……”作为伴随状语，修饰动词“are now drawing solid conclusions”，且由于是“having done”结构，因此修饰语中的动作发生在被修饰动词之前，表意合理。
【大意】 神经学家，在积累了近20年丰富的关于大脑及其从人出生到成年的发展过程的知识之后，现在正在对人类大脑如何增长和幼儿如何学会语言做出结论。
(B)Neuroscientists, having amassed a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
【错误】 平行结构：“and”两边应连接平行结构(功能一致，概念对等的结构)，但本选项“and”两边语法功能上无法平行。
(C)Neuroscientists amassing a wealth of knowledge about the brain and its development from birth to adulthood over the past twenty years, and are
【错误】 平行结构：见(B)。
(D)Neuroscientists have amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood,
【错误1】 修饰成分：非谓语动词“drawing”在本选项中作状语(动词的修饰语)，其逻辑主语为“neuroscientists”，与所修饰动词“amassed”的主语相同，这意味着“drawing”是动词“amassed”的伴随状语，根据与法要求，“doing”应伴随所修饰动词同时发生且同(逻辑)主语，但根据日常逻辑“drawing conclusion”(“下结论”)并不应伴随“amassed a wealth of knowledge”(积累知识)同时发生(应先积累知识后下结论)。
【错误2】 句子意思：根据日常逻辑，“drawing conclusion”(“下结论”)应是本句的句意重心，作为伴随状语表意不佳。
(E)Neuroscientists have amassed, over the past twenty years, a wealth of knowledge about the brain and its development from birth to adulthood,
【错误1】 修饰成分： 见(D)中【错误1】。
【错误2】 句子意思： 见(D)中【错误2】。
解题思路：
“and”两边本应存在平行结构，因此立即排除(B)和(C)。
(D)和(E)的“now drawing……”作为伴随状语，修饰关系不合理，也应排除。因此选择(A)。
