A modern reader of the Poema del Cid cannot fail to be struck by the general oddity of its verbal system, especially in the tenses of the past, where one finds perfects, preterites, imperfects, pluperfects seemingly interchanged in no meaningful pattern; consequently he leaves the work with an impression of confused tense relationships, an indication (he is convinced) of the lack of skill of the poet (or poets) and the impossible primitiveness of the language. There have been recent stylistic attempts to interpret the uses of the tenses, in particular those of the past, as functions of aspect rather than of time, or as poetic devices in the delineation of heroic character, or as specifically epic techniques of narration. Simpler explanations given earlier, which saw in the unusual frequency of the imperfect, for instance, nothing more than the need to meet the rhyme, have found little favor and have been supported only by intuitive arguments. But those who have rejected the earlier views have not provided conclusive proof of their assertions. In fact, despite the great scholarly interest in the language, metrics, and style of the Cid, there seems to be no study of the possible relationship between rhyme and verbal structure. As a contribution to the study of the Spanish epic as well as to the larger field of historical style and syntax, the present paper seeks to clarify the issues and to provide an objective basis for a conclusive determination of the problem.