are underlined, whereas periodicals and works that are portions of greater works are italicized. So, book titles, album titles, etc., are underlined, but chapter titles, article titles, and such, are italicized. Song titles are a fuzzy middle ground; if talking about the song in isolation, it's underlined, but if talking about it as part of an album, an opera, or the like, it's italicized.
If you like, I'll check my St. Martin's Handbook for English Grammar when I get home; it's the reference I use when I'm editing copy for books and stories. So now you've got an editor contradicting your teacher. That's trump. A teacher only tells you how it's done; I tell you how it's done if you want to get paid for it. ;-) |