Explanation I use in comments on student papers:
Too many of your sentences discuss parallel thoughts in a series in non-parallel syntax, which gives a sense that you’ve changed syntax and thought structures in midstream. Use parallel syntax for parallel thoughts to help your reader follow your logic.
For example, the following hypothetical sentence is hard to follow and awkward because it does not use parallel structure for parallel thoughts: “The poet tells us that he loved Lucy, she was loved by nature, and also he tells us that it was almost like he and nature competed for Lucy.” Here is the same sentence rewritten to take advantage of parallel structure: “The poet tells us that he loved Lucy, that nature also loved her, and that it was almost like he and Nature competed for her.”
