根据语法中的平行和从属结构原则，一个复合句中必须要有一个过渡词，否则句子是不符合语法规则的。过渡词作为一种关系指引词，一般由副词或起副词作用的短语承担。此外，代词、连词、上下文的近义词等也可作过渡词。要写出清晰流畅的文章，就需要把文章中各部分巧妙地连接在一起。这样可使文章自然而别致，并能层层展开主题句，完整地表达中心思想。而过渡词(Transitional Words)就是连接这些部分的纽带，使文章起、承、转、合，融会贯通，连成一体。下面我们就来了解一下各类过渡词的具体使用，如何起承转合构成一篇逻辑严谨的好文章。
一、 “起” ——用于开篇或引出扩展句
1. at first/ in the beginning 起初
2. at present 现在;当今
3. recently/ lately 最近
4. first/ firstly/ first of all 第一
5. generally speaking 一般地说
6. on the whole 总的说来
7. It is well understood that 众所周知
8. There goes a saying that 俗话说
9. for one thing..., for another/ also... 首先，其次
10. presently 此刻;现在
11. to begin with/ to start with 首先;第一
12. in general 一般来说
13. on the one hand, on the other hand 一方面，另一方面
14. As the saying goes, ’...’ 俗话说，...
二、 “承” ——用来承接上下文
1. by this time 此时
2. at the same time 同时
3. after a while 过了一会儿
4. after a few days 几天以后
5. second/ secondly 第二;第二点
6. in addition 另外
7. besides/ what’s more 另外
8. by the way 顺便提一句
9. in other words 换句话说
10. in particular/ particularly 特别地
//11.in the same way 同样地
12.obviously 明显地
13. no doubt 无疑地
14. for example/ for instance 例如
15. therefore 因此
16. indeed 的确
17. unlike 不象
18. certainly 当然
19. for another 其次
20. still 仍然
21.similarly 同样地
22. worse still 更糟的是
三、 “转” ——用来表示不同或相反的意见
1. in/ by contrast 对比之下
2. unfortunately 不幸地
3. though/ although 尽管
4. even though 即使
5. anyway 无论如何
6. after all 毕竟
7. all the same 依然;照样
8. in fact/ as a matter of fact 事实上
9. fortunately 幸运地
10. however 然而
11. in spite of 尽管;虽然
12. at the same time 同时;然而
13. otherwise 否则
14. on the contrary 相反
15. especially 尤其
16. There are two sides to everything. 凡事都有两面性
四、 “合” ——用于小结上文或结束本段落的内容
1. in a word/ all in all/ in conclusion 总之
2. to conclude/ to summarize 总之
3. in brief/ in short/ in summary 总之
4. on the whole 总体来说
5. above all 最重要的是
6. as a result 结果
7. obviously 显然
8. As far as I' m concerned 就我而言
9. Taking all these into consideration 考虑到
10. accordingly 因此
11. therefore/ thus 因此
12. as has been noted 如前所述
13. as I have said 如我所述
14. by doing so 如此
15. to speak frankly/ to be frank 坦白地说
16. It is quite clear that 很明显
17. There is no denying that 无可否认
18. Considering 考虑到