Over 400 examples! Mistakes in grammar or punctuation can be annoying to a reader and quickly draws attention away from what is being written. These types of mistakes cause the reader to focus on the grammar instead of what is being communicated, leads them to question on how well educated the person is, and significantly reduces the impact of your message. Proper grammar and punctuation not only helps you control the flow of writing, but also helps to accurately and effectively convey your mess