根据过渡词表示的语义和逻辑关系，我们可以分类为：
1) 举例
for example, for instance, as a case in point, as an illustration, such as, say, e.g.
2) 释义
that is, that is to say, in other words, so to speak, or rather, namely
3) 原因
because, because of, for, as, owing to, thanks to, due to, now that, since, as a result of, attribute to, in that
4) 条件
if, unless, whether, provided that, given, as long as, on condition that, otherwise
5) 让步
despite, in spite of, though, although, nevertheless, but, however, admittedly, it is true…but, after all
6) 结果
for this reason, therefore, consequently, accordingly, hence, as a result, thus, in short, in a word, to sum up, to conclude
7)比较
similarly, like, likewise, in the same way, much……, as much, no more……, than, just as…… so
8)对照
whereas, instead, however, unlike, on the contrary, in contrast, on the other hand, while, some……, others
9)层进
first, in the first place, to begin with, second, next, in addition to, besides, moreover, furthermore, third, finally
10)强调
indeed, in fact, certainly, particularly, above all, most importantly, worst of all
11)目的
in order to, in an effort to, so as to, in order that, for fear that, in case, least
12)先后
shortly after, earlier, later, afterwards, after, before, once, meanwhile, since, until, when, while, the moment, as soon as
13)指示
this, that, these, this accounts for, this helps explain, that's why
