We need more than words and grammar to communicate clearly. In speech, we use stress, pauses, and changes in pitch and volume to help the listener understand our message. These non-linguistic features of spoken communication help us to indicate to the listener whether we are making a statement or asking a question; whether we have expressed a complete thought or there is more to come; whether what we are saying is important or just a passing remark.

In writing, we use punctuation to convey some of this information to the reader. If used effectively, punctuation helps the reader to process the information in the text and make sense of our writing. However, if used inappropriately, punctuation may be an obstacle to comprehension, causing the reader to slow down, reread portions of text in an attempt to understand, and even lose track of the argument. These pages contain some guidelines on the use of punctuation marks commonly used in academic writing: