The purpose of this paper is to describe and classify various relics found in English and to account for linguistic motivations behind the existence of relics by looking at their linguistic contexts. Although there are previous studies of relics, most of them focused on either a single particular form or a mere taxonomy of some relics, even the latter being rare. No systematic studies have been done about the linguistic context retaining relics. The examination of phoneme, morpheme, meaning, word, construction, and word order relics shows that compounds, affixation, and idiomatic phrases tend to retain relics. It is argued that the formulaic property of those linguistic expressions motivates the occurrence of a relic, whereby the syntactic and semantic structures of the expressions become so opaque as to be unfeasible for a linguistic change.