Narratives (sequences of purposively related concrete situations) and arguments (reasoning and conclusions in an attempt to persuade) are distinct cornerstones of human discourse. While theories of their linguistic structures exist, it is unclear which theorized features influence perception of narrative and argument quality. Furthermore, differences in their usage over time and across formal versus informal mediums remain unexplored. Thus, we use an original dataset of news and Reddit discourse (consisted of >10,000 clauses), annotated for clause-level discourse elements (e.g., generic statements vs. events; Smith, 2003), and their coherence relations (e.g., cause/effect; Wolf & Gibson, 2005). We identify the features that correspon...