连接词是用于连接单词，词组或者是从句用的。
例如：They may have used wood and skins, but these have rotted away.
Call me when you get home.
并列（对等）连词Co-ordinating Conjunctions
并列对等连词比如：and but or nor for so yet　.这些词可以去链接个别的单词，短语，　及独立的从句。并且要注意，你可以运用but 和for作为介词。在下面的句子中突出的部分是并列连词
Apple and orange is my favorite fruit 在这里and 连接了两个名词
This movie is particularly interesting to feminist film theorists, for the screenplay was written by Harry。在这里for 被用于连接了两个独立的分句
Daniel’s uncle claimed that he spent most of his youth dancing on rooftops and swallowing goldfish 这里的并列连词and连接了分词短语（dancing on rooftops 和 swallowing goldfish 作副词来描述动词spend)
连接主语从句的连词Subordinating Conjunctions
连接主语从句的连词引导从属句子并且暗示独立从句和从属从句的关系（relationship among the independent clause(s) and the dependent clause(s).）
最常用的连接主语从句的连词有after although as because before how if once since than that though till until when where whether 以及while
例句 After she had learned to read, Mary who is at 40 felt more fulfilment 这里的连词after 引导从属从句”after she had learned to read.”
If the paperwork arrives on time ,your cheque will be mailed on Monday 很类似 这里的连词if 引导从属从句“if the paperwork arrives on time “
相关连词 Correlative conjunctions
相关连词大多呈双出现，比如both…and ,either…or, neither…nor, not only…but also,so…as,whether…or
Both my brother Jimmy and my sister work in the steel plant.在这里correlative conjunction “both…and”用于连接两个名词短语“my brother”和“my sister”
Bring either a Jello salad or a potato scallop 这里的“either…or”连接了两个名词短语
Chris is trying to decide whether to go to medical school or to go to law school在这里相关连词连接了来年改革不定式短语“to go to medical school” 和 “to go to a law school”
在平常的四级学习中，为了加强对连词的记忆，熟练将连词运用在句子当中，一般把连接词与连接语分为以下三类：
　　1.表明事件发生的时间顺序
　　then, first, at once, next, after that, previously, while, when, the following day, etc.
　　2.表明文章的组织结构
　　1）Listing: firstly, in the first place, secondly, thirdly, my next point is, last/finally, etc.
　　2）Illustrating: for example/ for instance, to illustrate, an example/ instance of this is, let’s take………, take…. for example, etc.
　　3）Re-stating: in other words, that is to say, to put it another way, let me put it this way, or rather, namely, etc.
　　4）Referring: in this respect, in that connection, as we said, apart from this, etc.
　　5）Resuming: to resume, to return to the previous point, getting back to the argument, etc.
　　6）Summarizing: to sum up, in short, it amounts to this, what I have been saying is this, etc.
　　7）Emphasizing: it is worth noting, I would like to direct your attention to, let us consider, we must now turn to, I shall begin by, etc.
　　3.表明作者的观点、态度
　　1）Introducing（or emphasizing）further evidence: moreover, furthermore, in addition, what’s more, as well, etc.
　　2）Cause: because （of）, since, owing to, on account of, due to, as a result of, etc.
　　3）Effect: as a result, hence, therefore, consequently, thus, so, etc.
　　4）Contrasting: in / by contrast, on the contrary, on the other hand, nevertheless, whereas, while, yet, however, but, etc.
　　5）Comparison: in like manner, likewise, in the same way, similarly, in comparison with, etc.
　　6）Purpose: to this end, for this purpose, with this in mind, in order to, so that, etc.
　　7）Intensification: indeed, in fact, in any event / case, at no time, to tell the truth, etc.