One of the greatest pieces of advice that I got was that writers should read the works of excellent writers and learn from them. i did this a lot with the short story collections of the writer Tobias Wolff. What I learned from his writing is sentence structure. But one thing I noticed about him is that he didn't have commas in places where I thought they should be. I thought this was an error on my part, since critics and I loved his writing, so I started to not use commas in those "certain places." Here are a few sentences that I made, and I'll show you ones from Wolff. Where would commas be needed in these sentences? "I pulled my suitcase, and its wheels rolled along the floor until I reached the sidewalk. At the crosswalk the pedestrian signal showed a red hand as cars passed, blowing wind against my body. After five minutes a walking man’s white silhouette appeared, and I crossed the street. I stopped in front of the subway station." I was told that commas were needed between crosswalk and the, and minutes and a. What do my fellow writers think? - Wolff, from his short story "Hunters in the Snow."