The following groanworthy errors are from Just My Typo, compiled by Drummond Moir. It’s all too easy to write a word you know well, a word that is close to the one you meant. We’ve all done this. Careful proofreading will prevent a red face.
As I’ve often nagged you, if you proofread silently at your normal pace you will read what you think you wrote, not what you actually wrote. You need to slow down and read out loud. Quietly is fine. The authors of the following sentences obviously neglected to do so:
• Doctors now treat their patients with ultra-violent rays.
• A polygon is a man who has many wives.
• In biology today we digested a frog.
• In the Middle Ages, people lived in rough huts with mating on the floor.