"Do you call Sirius and Remus by their last names?" Lily knew he didn't, she hadn't ever heard him refer to them as anything other than their first names. Her eyes skimmed over what he had written so far. "A semicolon should go there. It's a new thought, but not so much to warrant a new sentence," she pointed to a particularly long sentence.
Lily met his eyes, "I know, but I hope you try to break the habit. If I'm calling you James you need to be calling me Lily. How about you start now, say my name."