"An" is an indefinite article, the form of "a" used before a vowel sound. Articles are minor words in title case, so "an" stays lowercase in the middle of a title and is capitalized only by position.
This guide covers how Chicago, MLA, APA, AP, AMA, the New York Times, Wikipedia, and Bluebook each treat "an", with examples and the mistakes that trip writers up.
Quick Answer
In Chicago, MLA, APA, AP, AMA, NYT, Wikipedia, and Bluebook, "an" stays lowercase in a title unless it is the first word, the last word, or directly follows a colon. The rule is identical to "a" and "the": articles are never capitalized mid-title.
You can apply this automatically with the title case converter at the top of the page.
Quick Reference: "An" by Style Guide
| Style Guide | Capitalize "An"? | Rule |
|---|---|---|
| Chicago (CMOS) | No | Articles lowercase unless first or last word |
| APA (7th edition) | No | Articles lowercase mid-title |
| MLA | No | Articles lowercase unless first or last |
| AP | No | Articles always lowercase mid-title |
| AMA | No | Articles lowercase mid-title |
| New York Times | No | Articles lowercase mid-title |
| Wikipedia | No | Articles lowercase mid-title |
| Bluebook | No | Articles of 4 or fewer letters lowercase |
Real Titles That Use "An"
- An American Tragedy by Theodore Dreiser. "An" capitalized as the first word.
- The Making of an Icon. "an" lowercase mid-title.
- Portrait of an Artist. "an" lowercase mid-title.
