The Chicago Manual of Style

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The Chicago Manual of Style is the most widely used resource for American English style, grammar, and punctuation. If you’re working on any kind of writing project and need a solid reference that provides answers for how to consistently apply style and grammar, then this is the book for you.

Often called Chicago or CMOS, the text was originally published in 1906 with just 200 pages under the lengthy, albeit descriptive title: Manual of Style: Being a compilation of the typographical rules in force at the University of Chicago Press, to which are appended specimens of type in use. Yes, that’s a mighty long title.

In 2024, the eighteenth edition of The Chicago Manual of Style was published with 1,192 pages. It is available in hardcover, and there’s also a handy online edition to which you can subscribe, for a fee.

Chicago is so widely used because it can be applied to almost any type of writing. It’s extremely flexible and offers writers options for various formats. Many smaller, niche-oriented style guides are based on the guidelines set forth in Chicago, making it the foundation for most writing styles and grammar usages found throughout America.

What is a Style Guide?

There is a significant difference between a style guide and a grammar guide. A grammar guide will address the formal rules of language, rules that are applicable across any style, form, or format.

A style guide addresses all the gaps in grammar, and there are many. It also provides a set of guidelines that writers can use to format their work, often with an emphasis on citations. Adhering to these guidelines keeps your writing clear and consistent. If you’ve ever read a document or book that sometimes wrote out numbers (one, two, three) and other times used numerals (1, 2, 3) or used the serial comma in some sentences but not in others, you know how confusing and inconsistent written works can be when writers and editors don’t use a style guide.

Finally, many style guides incorporate the rules of grammar, so they address a wider range of questions and writing issues. Chicago is one such style guide. If you’re looking for a general-purpose writing resource that you can turn to for style and grammar, you’ve just found the holy grail.

Eighteenth Edition

The latest edition of Chicago gives greater consideration to diversity, inclusion, and accessibility. Previously focused on nonfiction, this edition includes fiction and other creative forms and genres, addressing elements such as dialogue. Attention is given to the needs of self-published authors as well. Sections on citations have been reorganized and mathematics editing has been integrated more appropriately for general use. Chicago routinely updates for the ongoing development of technology, and this edition is no exception; it covers AI and open-access publishing models. The manual also incorporates changes that better reflect real-world usage.

More Writing Resources

If you’re not ready for a style and grammar guide that has over 1,000 pages, then you might be more comfortable starting out with something slimmer, like Strunk & White’s The Elements of Style (4th Edition). If you’re writing for a particular publication, then you should check with the editor or manager to see if there is an established style guide that you should use. When no other style guide is specified, Chicago is the one to use, and it’s worth the investment.

For more recommendations, visit the writing resources section of Writing Forward, and keep writing!