The document discusses the prefix "re-", which means "to do something again". It provides examples of words that use this prefix, such as rewrite, redo, and rearrange. The document explains that adding "re-" to the beginning of words like charge and marry creates new words meaning to do that action again, like recharge and remarry. It encourages checking the root word after removing the prefix. Finally, it lists additional words that incorporate the "re-" prefix.