关系词，即体现句子之间关系的词或词组。也有不少人称之为信号词，或者是连接词。不管在雅思听说读写四门中的任何一门都需要用到这类词，以使得句子更加流畅，句意更加明晰。分析认为，关系词可分为两大类：
1. 同向关系词
同向关系词，即用上此类词或词组，句子内部或句子间的方向没有发生改变，只是根据前面的句意进一步延伸和细化。将其归纳为：
举例关系词：for example, for instance,e.g., such as, like, take sth for example.
类比关系词：like,alike, similar, same,as
选择，并列和递进关系词：or,either…or, and, as well,also, besides, apart from, in addition, what’s more,furthermore, moreover
因果关系词：表示由引起的，后接原因的词或词组：because，be cause of，as a result of, as a consequence of, due to, result from, be attributed to, be contributed to, arise from, owing to, thanks to, in that
表示导致，后接结果的词或者词组：so, therefore, thus, as a result, as a consequence, lead to, result in, attribute to, contribute to, give rise to, bring about, generate
总结关系词：in conclusion, to conclude,to sum up, in sum, all in all, in brief
2. 逆向关系词
逆向关系词，即用上此类词或词组，句子内部或句子间的方向发生改变，前后句子意思形成相反关系。总结发现，这类词包含：
否定关系词：not,none, no, never, non-,dis-, un-, in-, im-, -less, few, little, hardly, barely,seldom, neither…nor
转折和让步关系词：but,however, yet, nevertheless,nonetheless, in fact, actually, despite, in spite of, although, even though,though
对比关系词：unlike,by contrast, in contrast, on the contrary, conversely
(注：以上各类关系词中所举的例子仅仅只是常见的一部分)