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，关系词可非分两大类：
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，because 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.
