语法是GMAT考试比较特殊的部分，为什么这么说呢?因为GMAT语法贯穿在各个考试部分，而且对于考试的基础知识要求比较高。这里小编给GMAT入门考生分享的是after的使用技巧：
1 after doing 相关问题
220. (GWD-24-8, OG12-86)The results of the company's cost-cuttingmeasures are evident in its profits, which increased five percent during thefirst three months of this year after it fell over the last two years.
A. whichincreased five percent during the first three months of this year after it fell
B. whichhad increased five percent during the first three months of this year after ithad fallen
C. whichhave increased five percent during the first three months of this year afterfalling
D. with a five percent increase during the firstthree months of this year after falling (C)
E. with a five percent increase during the firstthree months of this year after having fallen
答案选C，但解释上有点问题我不明白：下面是语GMAT语法笔记上对于B和C的解释：
B. after it had fallen时态上没有问题，可以与over the last two years搭配，但是不如after falling简洁
C. Correct;afterfalling简洁，状语从句的省略
求助GMAT考试讨论：可是我不理解为什把after doing理解为状语从句的省略。我觉得这里不是省略!!!
状语从句的省略：从句主语和主句主语一致，并且包含be。。。从句主语和be可以省略。when，although ，等词引导时间状语从句，让步状语从句等时，可以用这种形式来简洁表达。
但是如果把这里的after doing 理解为 after it have/had been falling。我觉得也不能清晰的表达出原文所想表达的时态先后关系。而且如果这里 fall是进行时表达一直在下降，这里也是不对的吧。
我认为GMAT入门的考生应该这样理解：
after doing 作状语，表达其修饰的动作之前发生的动作，其修饰的动词和after后面的动词动作发出者要一致。如此表达最能体现出二者的先后关系。
The best way to extract the flavor from saffron threads is to soak them in liquid after pounding
them 。。。这里pounding作状语，修饰的是soak。 虽然整句话都没有出现pound的动作发出者，但soak和pound二者逻辑上的动作发出者一致。
另外提一句：
AlienX: after having done something是不可能对的
1)after已表示the sequence of events.没有必要用having done来表示前后
2)可是after someone/something has/have done something是acceptable; 如果变成after someone/something did something也可以
上述就是小编分享的GMAT考试语法after的使用技巧，千万不要小看它在GMAT语法中的作用。语法的复习需要一步一步的走，GMAT入门的考生要把握好每一个细节部分，这样考试才能得高分。