Result
Only at the start. "An" is an article, and articles stay lowercase in the middle of a title in every major style guide. Capitalize it when it opens the title ("An American in Paris") or a subtitle, and lowercase it everywhere else.
"An" by Style Guide
| Style guide | "An" mid-title | Why |
|---|---|---|
| AP | Lowercase | Articles (a, an, the) stay lowercase mid-title |
| APA | Lowercase | Articles (a, an, the) stay lowercase mid-title |
| Chicago | Lowercase | Articles (a, an, the) stay lowercase mid-title |
| MLA | Lowercase | Articles (a, an, the) stay lowercase mid-title |
| AMA | Lowercase | Articles (a, an, the) stay lowercase mid-title |
| Bluebook | Lowercase | Articles (a, an, the) stay lowercase mid-title |
Examples in Chicago Style
- An American in Paris
- How to Write an Essay Outline
- Memoirs of an Invisible Man
- Anatomy of an Outage
When "An" Is Capitalized
- First word: "An Inspector Calls."
- First word of a subtitle: "Remote Work: An Honest Review."
- Last word: almost never happens, but AP, Chicago, and MLA would capitalize it.
Choosing "A" or "An"
Capitalization never changes which article you use. The choice follows the sound of the next word: "an SEO audit" (the letter S is pronounced "ess"), "a URL" (pronounced "you"). See "a" and "the" for the other articles, or articles in title case for all three side by side.
Real Titles With "An"
- An American in Paris (George Gershwin): first word
- Memoirs of an Invisible Man (H. F. Saint): lowercase mid-title
- An Inspector Calls (J. B. Priestley): first word
"An" in Sentence Case
APA reference lists, many news sites, and most UI text use sentence case instead of title case. There, only the first word and proper nouns get capitals, so "an" is lowercase unless it starts the title: "How to write an essay outline." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "an" be capitalized in a title?
Only when it is the first word of the title or subtitle. Otherwise it stays lowercase.
Is "an" capitalized in AP style?
Not mid-title. AP lowercases the articles a, an, and the.