The notion of ‘prediction’ as a prospective rhetorical device in improving the reading abilities of ESP learners is significant on the basis of the assumption that once the rhetorical structure of the text is understood by the learner, he is able to use this to predict the type of forthcoming information. This study explores the possibility of linking the textual indices of ‘Predictive Categories’ with the understanding of content knowledge. The article reports on descriptive qualitative research based on data comprising 10 chapters from 5 textbooks in the field of Civil Engineering, applying a model of discourse analysis designed by Tadros (1981), as the method of the study, using the notion of prediction. The Six Predictive Categories introduced by Tadros (1981) underpinning the model, include Enumeration, Advance Labelling, Reporting, Recapitulation, Hypotheticality and Question were explored continuously in the selected texts. What makes this study significant is that a new Predictive Category has been identified in which two or three Predictive Categories are exactly overlapping each other. Basing our assumption on the pedagogical benefits gained by ESP learners, teachers, and material designers, it is suggested that the consciousness-raising of these categories has valuable benefits for all ESP community members. پرونده مقاله