Result
Yes. "When" is capitalized in AP, APA, Chicago, MLA, and AMA title case, whether it is a question word ("When Will It End?") or a subordinating conjunction ("What to Do When Traffic Drops"). The one exception is Bluebook, which lowercases conjunctions of four letters or fewer, so it keeps "when" lowercase when it joins two clauses.
"When" by Style Guide
| Style guide | "When" mid-title | Why |
|---|---|---|
| AP | Capitalize | Conjunctions of four or more letters are capitalized, and adverbs always are |
| APA | Capitalize | Words of four or more letters are capitalized |
| Chicago | Capitalize | Adverbs and subordinating conjunctions are capitalized |
| MLA | Capitalize | Adverbs and subordinating conjunctions are capitalized |
| AMA | Capitalize | Adverbs and subordinating conjunctions are capitalized |
| Bluebook | Capitalize | Capitalized as an adverb; as a conjunction ("Duty to Act when Asked") Bluebook keeps it lowercase |
Examples in Chicago Style
- What to Do When Traffic Drops
- When to Use Title Case
- When Harry Met Sally
- The Day When Everything Changed
Related Words
"Where", "while", and "if" are also subordinating conjunctions. "Where" and "while" are capitalized everywhere except as Bluebook conjunctions, while short "if" splits the guides further. For the words that stay lowercase, see the full list of words that stay lowercase.
Real Titles With "When"
- When Harry Met Sally... (1989 film): first word
"When" 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 "when" is lowercase unless it starts the title: "What to do when traffic drops." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "when" be capitalized in a title?
Yes, in AP, APA, Chicago, MLA, and AMA. Bluebook lowercases it only as a conjunction.
Is "when" capitalized in APA?
Yes. "When" has four letters, and APA capitalizes words of four letters or more.
Is "when" capitalized in Chicago style?
Yes. Chicago capitalizes adverbs and subordinating conjunctions.