By Phoebe (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia CommonsThere is a fine line when it comes to copy-editing and copy-reading. On the one hand, as a copy-editor, it is your responsibility to correct all grammar mistakes, make sure the writing flows, and fact-check. But on the other hand, you also have to be mindful of the writer’s style, and be courteous when making suggestions.