When you're title-casing a piece of writing, the small word "a" creates more confusion than it deserves. Style guides treat short articles differently from major words, so the rule shifts depending on whether you're following Chicago, MLA, APA, or AP. Here is a clean breakdown of when to capitalize "a" in a title and when to leave it lowercase.
Quick Answer
In Chicago, MLA, APA, and AP styles, "a" stays lowercase in a title unless it is the first word, the last word, or it directly follows a colon or dash. That rule holds across every major American style guide, so if you stick to it you will be correct in almost every situation.
You can also paste any title into the free title case converter at the top of the page to apply these rules automatically.
Chicago Manual of Style
The Chicago Manual of Style is the standard for book publishing, academic writing, and most long-form work. Chicago capitalizes major words in a title (nouns, pronouns, verbs, adjectives, and adverbs) but keeps articles like "a," "an," and "the" lowercase unless they are the first or last word.
Example: A Tale of Two Cities capitalizes "A" because it leads the title. The History of a Quiet Town keeps "a" lowercase because it sits in the middle.
MLA Style
The Modern Language Association (MLA) style is the dominant guide in the humanities. MLA matches Chicago on this point: capitalize the first, last, and principal words of a title; keep articles, prepositions, and short coordinating conjunctions lowercase unless they appear at the start or end.
Under MLA, you would write A Room of One's Own with a capital "A" only because "a" leads the title. In The Story of a Lost Generation, "a" stays lowercase.
APA Style
American Psychological Association (APA) style is the standard in the social sciences. APA follows title case for headings and source titles, and treats "a" the same as the other guides: lowercase unless it is the first word, the last word, or follows a colon.
Example: Sleep deprivation: A meta-analysis capitalizes "A" because it directly follows the colon.
AP Style
Associated Press (AP) style is used by most newsrooms and online publications. AP's title case rule capitalizes every word of four letters or more, plus all nouns, verbs, and other principal words. Articles like "a," "an," and "the" stay lowercase mid-title unless they are the first or last word.
The Colon and Dash Exception
Across every style guide, "a" gets capitalized when it directly follows a colon or dash in a title. The text after a colon or dash is treated as a new title, so the first word starts fresh with a capital letter even if that word is "a."
- The Long Road: A Memoir (capital "A" after the colon)
- Marketing Fundamentals: A Practical Guide (capital "A" because it starts the subtitle)
Putting It Together
The short answer for "a" is consistent across Chicago, MLA, APA, and AP: lowercase unless the word starts the title, ends the title, or follows a colon or dash. If you want a deeper look at how each guide handles capitalization beyond this one word, the title case styles guide breaks down the full rules side by side.
