How to Use Italics
You don't have to be Italian.
The Origin of Italic Type: Handwriting by Niccolò de' Niccoli (1364–1437)
Today we’re going to talk about italics, that slanted type that you sometimes see amidst regular roman type.
Following the Rules
Open up any style guide and it'll give you a list of items that need to be italicized. The important thing to remember is that if your school or business follows a certain style guide, you should follow it too. The four main style guides that you may be asked to follow are the Associated Press Stylebook and Libel Manual, used by journalists; the Chicago Manual of Style, used by many publishers; and the Publication Manual of the American Psychological Association and the MLA Handbook for Writers of Research Papers used by many students. All four contain detailed rules on when to use italics. The AP Stylebook is easy: the AP doesn't use italics. The rest are a little more nuanced, but you’ll be relieved to know that we won’t be listing all the rules here in the podcast.
Instead, we’re going to give you a medium-sized list of things you probably should italicize. Just be sure to double-check the style guide you’re supposed to use, as rules vary. Here goes: foreign words not yet assimilated into English—more on that later; legal citations; letters of the alphabet when you’re referring to them as letters; scientific names; titles of works, including books, plays, short stories, very long poems, newspapers, and magazines; titles of movies and radio and television series; names of operas and long musical compositions; and names of paintings and sculptures (1). You might also be asked to italicize the names of famous speeches, the titles of pamphlets, the names of vehicles (such as Challenger), and words used as words (2).
Although grammatical texts haven’t caught up with modern technologies like blogs and podcasts and don’t specifically mention these as far as italics, it would probably be safe to use italics to refer to them. That's what we do on the Grammar Girl website. Alternatively, though, you could probably also use quotation marks to refer to a blog or podcast name.