想要迅速提高GMAT语法考试成绩，考生就需要熟练掌握一些GMAT语法考试中的必备知识点，并在解题的过程中灵活运用。下面就来对GMAT语法必备知识点进行简单的介绍，希望能够为同学们备考GMAT语法考试带来帮助。
首先Not only…..but (also)表示的关系是递进, 其中also可以省略
……….But/but also表示的是转折. 在but also中, ring_cheng认为also不属于重复, 所以应当保留.该观点尚未证实.
not only ...but also表示并列，不能表示转折，不要有先入为主的感觉认为not only...but also必须一起出现。单独出现but also是可能的，参见大全74
All-terrain vehicles have allowed vacationers to reach many previously inaccessible areas, but they have also been blamed for causing hundreds of deaths, injury to thousands, and seriously damaging the nation’s recreational areas.
(A) deaths, injury to thousands, and seriously damaging
(B) deaths and injuring thousands, and serious damage to
(C) deaths, thousands who are injured, as well as seriously damaging
(D) deaths and thousands of injuries, as well as doing serious damage to(D)
(E) deaths, thousands are injured, and they do serious damage to
关于not only…but also.. 的用法,我根据前人的发言并结合GMAT的思路挑出了这几条:
1.在正常语序中: not only … but also 应连接两个相对称的并列成分。例如：
Not only Mr Lin but also his son joined the Party two years ago. (连接两个主语)
I not only play tennis but also practise shooting. (连接两个谓语动词)
He plays not only the piano but also the violin. (连接两个宾语)
在正常语序中: 短语本身不可以加入其它成份，比如变成：not only...but it also...是错误的(因为破坏了平衡)。
如大全中：
125.The winds that howl across the Great Plains not only blow away valuable topsoil, thereby reducing the potential crop yield of a tract of land, and also damage or destroy young plants.
(A) and also damage or destroy
(B) as well as damaging or destroying
(C) but they also cause damage or destroy
(D) but also damage or destroy(D)
(E) but also causing damage or destroying
Choice D, the best answer, correctly employs the correlative construction not only x but also y, where x and y are grammatically parallel and where both x and y (damage and destroy) apply to young plants. Choices A, (not only... and also), B (not only... as well as), and C (not only... but they also) violate the not only... but also paradigm. Moreover, B contains terms (blow... damaging) that are not parallel. In C and E, damage is used not as a verb with young plants as its direct object but as a noun receiving the action of cause; consequently, these choices fail to state explicitly that the damage is done to young plants. E also violates parallelism (not only blow... but also causing)