You do if you want to understood by the average American. Please remember that simple words do not imply simple ideas. As Hemingway said when criticized for hi

You do if you want to understood by the average American. Please remember that simple words do not imply simple ideas. As Hemingway said when criticized for his simple language, Poor Faulkner. Does he really think big emotions come from big words? He thinks I don’t know the ten-dollar words. I know them all right. But there are older and simpler and better words, and those are the ones I use.