Result
Yes. "Why" is an adverb ("Why It Matters") and every style guide capitalizes it in a title, even though it is three letters. The length cutoffs in AP, APA, and AMA only apply to prepositions and conjunctions.
"Why" by Style Guide
| Style guide | "Why" mid-title | Why |
|---|---|---|
| AP | Capitalize | Adverbs are major words |
| APA | Capitalize | Adverbs are major words |
| Chicago | Capitalize | Adverbs are major words |
| MLA | Capitalize | Adverbs are major words |
| AMA | Capitalize | Adverbs are major words |
| Bluebook | Capitalize | Adverbs are major words |
Examples in Chicago Style
- Why It Matters
- Here's Why Your Headline Failed
- Why Title Case Still Matters
- The Reason Why
The other question words are capitalized too: "how", "what", "when", and "where".
For the short list of words that do stay lowercase, see the full list of words that stay lowercase.
"Why" 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 "why" is lowercase unless it starts the title: "Why it matters." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "why" be capitalized in a title?
Yes. "Why" is an adverb, and every style guide capitalizes adverbs in title case.
Is "why" capitalized in APA?
Yes. APA capitalizes major words, including adverbs, regardless of length.