Tighten Your Copy Yourself
Cut long sentences in two.
This goes beyond run-on sentences. Most of your long sentences are likely grammatically correct. BUT long sentences often contain multiple ideas, so they can easily lose the reader’s focus because they don’t provide a break, leading readers to get stuck or lose interest, and perhaps the reader might get bored and go make dinner instead.*
See what I mean? If you find a comma-heavy sentence in your manuscript, try giving each idea its own sentence. By giving the break, readers keep focus and maintain interest. Dinner goes by the wayside, and though hungry, your reader doesn't get bored.
*I borrowed this sentence example from a blog post I read years ago. I think it's great at making the point. I can't remember where I found it though but wanted to acknowledge it wasn't of my own creation.