考研英语写作的时候，写好段落也是很重要的。我们平时写的文章往往都是由几个段落组成，和句子一样，段落也是为文章的中心思想服务，形成一个有机的整体。跨考考研张老师认为好的段落必须是意思完整，语义连贯，完全体现文章主旨中心，同时又是层次分明，结构严谨，逻辑关系应用合理的。
一、段落的组成
一个段落由三部分组成：
1.主题句(Topic Sentence):点出段落的主题(谈论什么)。
2.扩展句(Developing Sentence):说明和支持主题。
3.结尾句(Concluding Sentence):得出结论。
二、段落的主题
一篇文章有中心意思，也就是题目。而每个段落则有段落主题，段落主题是为文章中心思想服务的。
每个段落只能有一个主题(central idea)，它用一个句子加以表达，所以称为主题句。主题提出后需要很多结构严谨的句子来支持和说明，称为扩展句。最后得出一个结论，并用一个结尾句表达。参看下面段落：
(主题句)Slavery in the United States existed almost unchanged for 250 years.(扩展句1)During this time, most slaves were not allowed to marry or to raise families.(扩展句2) Usually they were not allowed to learn to read.(扩展句3) It was very dangerous for a slave to travel, since even free Negroes could be kidnapped and sold at any time. (结尾句)Under these conditions, it was almost impossible for them to organize to help each other.
三、写好主题句
定义：主题句为一个完整的句子，用以概括、叙述和说明该段的主题。
位置：主题句一般位于段首，也可置于段尾或段中，考生最好放在段首，这样较易掌握和构思。例如：
位于段首：在英文中，大部分段落的第一句便是主题句。开门见山地提出问题，后面的扩展句围绕主题句加以说明、支持、补充和解释。
Learning English at college is different from learning English at the middle school. In the middle school, the students are more dependent and passive. But college students must solve most of the problems by themselves. They will have to consult the dictionaries and reference books by themselves and prepare their lessons.
位于段尾：主题句位于段尾便于总结全段的内容，给读者以深刻的印象，是写作中的一种演绎方法。
Similarly, in order to write successful answers to essay questions on history or anthropology examinations, a student must arrange the relevant facts and opinions according to some accepted pattern of paragraph structure. And certainly when a student writes a book report for English, or a critiques for politics studies, or a term paper for sociology, style and organization are often as important as content. Clearly, the ability to write well organized, concise paragraphs and essays is essential to a student’s success in almost all university courses.
位于段中：位于段中的主题句起承上启下的作用，这类主题句多起转折作用，一般由“but, however, yet, anyhow, nevertheless”等词连接，用于引起下文。
What we teach ourselves sometimes indeed in more useful than what we learn from others. Some great men had little or no schooling. But these great men probably studied harder by themselves than most boys do in school. The greatest minds do not necessarily of those who have never been able to distinguish themselves at school, have been very successful in life later. It has been said that Wellington and Napoleon were both dull boys at school, and so were Newton and Albert Einstein.