主谓搭配。。。不知道怎么解释，反正就是主语和谓语动词配对就行。不能单数对复数。平行结构就是例如not only, but also这样的结构，前后要完全一致。说不清楚，来个题目。题目来自GMAT OFFICIAL GUIDE 10TH EDITION语法部分的第71题。
The original building and loan associations were organized as limited life funds, whose members made monthly payments on their share subscriptions, then taking turns drawing on the funds for home mortgages.
(A) subscriptions, then taking turns drawing
(B) subscriptions, and then taking turns drawing
(C) subscriptions and then took turns drawing
(D) subscriptions and then took turns, they drew
(E) subscriptions and then drew, taking turns
句子中的then是用在从句whose里表示递进关系的，因此，它后面的动词就应该和members后面的动词一致。判断只有C,D选项正确。D选项错在句子之间没有连词，而且用THEY的话即使有连词，也冗余了。C选项正确。
句法，说白了也是一句话：一个句子只有一套主谓结构。看起来也很简单，问题就是，能不能在一个超长的句子里（里面包括从句，从句里还有从句，还有同位语，超长状语等等）快速的找出主语和谓语，是提高你阅读速度和理解的关键。先来个简单的句子看看。（来自GMAT OG 10ED 阅读第三篇）
MESBIC’s are the result of the belief that providing 《---主谓已经出现，同时出现从句
established firms with easier access to relevant management
techniques and more job-specific experience, as 《---对称结构
well as substantial amounts of capital, gives those firms 《---从句里的从句
a greater opportunity to develop sound business foundations
than does simply making general management 《---又一对称结构
experience and small amounts of capital available.
不知道大家看明白了没。我就不翻译了，中文太差，呵呵。。。语文总不及格。。。
再来个，这句也不难。
The methods that a community advises to perpetuate itself 《---主语+从句出现
come into being to perserve aspects of the cultural 《---谓语在这里
legacy that that community perceives as essential. 《---又是一从句，两个that连一起，看懂了么？
主语是方法，一个社会设计出来用来保存自己的方法。谓语是形成，方法形成是为了保存文化遗产，是这个社会认为必要的文化遗产。。。有点绕，哈哈。
这里不谈学术性写作，就说说考试的作文。（各种考试，TOEFL,GMAT,IELTS...）上面三种我都有考过，就像八股文一样，有自己的套路。在考试之前总结出自己的模板，考试的时候在根据具体的题目往上套就可以了。打个比方，在开头写上这样的一句话，Recently, there is much debate over the issue that... Different people have different answers due to their respective point of view. 不说全部的题目吧，应该绝大部分都可以吧？或者再结尾段写On balance, my view is that...另外中间的段落也可以写一些套路的话，比方说In the second place, much evidence has shown that...
。但是这个单词被分成三个部分，再看看，这不是TNT嘛！三硝基甲苯！BINGO! 马上查字典验证，果然没错。然后再把老婆叫来炫耀一番，让她崇拜一下，哈哈。。。