This document discusses concepts of cohesion and coherence in discourse analysis. It defines cohesion as the links that hold sentences, ideas and details together clearly and coherence as the quality of being logical and consistent. Cohesion and coherence are important to help readers understand ideas as intended and achieve a consistent relationship among text elements. The document outlines different types of grammatical cohesion including reference, substitution and ellipsis. Reference can be exophoric, endophoric, personal, demonstrative or comparative. Substitution can be nominal, verbal or clausal. Ellipsis involves the deletion of words implied by context.