In academic writing, occasions arise that require headline-style capitalization, sometimes referred to as title case. Specific instances are dependent on the style manual, but could include titles of chapters, articles, books, journals, or other works. Title case may also be used for section headings or captions. Long ago, I learned to capitalize the first and last words of a title, as well as any other important word. What makes a word important? It turns out that the answer depends on your particular style manual. Let’s take a look at how headline-style capitalization works in APA Style, and then how Chicago Style’s rules differ.
Title Case in APA Style
Three factors determine whether a word should be capitalized when using title case in APA Style (title case is APA's term): its position in the title, its grammatical function, and the length of the word. Follow these guidelines when using title case:
Capitalize the first word of both the title and the subtitle, if there is one. The subtitle would include any part of the title that follows a colon, em dash, or any sentence-ending punctuation, such as a question mark or exclamation point. This rule takes precedence over all others.
Capitalize all nouns, pronouns, adjectives, adverbs, and verbs, regardless of their length.
Capitalize conjunctions and prepositions with four or more letters; lowercase them if they have three letters or fewer.
Lowercase the articles a, an, and the.
Capitalize both parts of hyphenated words.
Headline-Style Capitalization in Chicago Style
Chicago Style differs from APA style in its guidelines for headline-style capitalization in several ways (headline-style is the term used in The Chicago Manual of Style). Most of those differences arise because Chicago does not factor length into determining the importance of a word; instead, it relies only on its position in the title and its grammatical function.
In Chicago Style, the last word of the title and subtitle should always be capitalized (unless the last word is the second part of a species name). As a practical matter, the final word will be capitalized in APA, too, because it is highly unlikely that a short preposition, conjunction, or article would appear at the end of the title.
Chicago Style considers all prepositions to be minor words, regardless of their length, so always lowercase prepositions. This rule is likely the most significant difference due to the common usage of prepositions in titles.
As with APA, the coordinating conjunctions and, but, or, for, and nor should be lowercase, but in Chicago, all other conjunctions should be capitalized regardless of their length. This rule means that three conjunctions that are lowercased in APA Style–if, so, and yet—are capitalized in Chicago Style.
Lowercase the word to when using it as a preposition or as part of an infinitive (but not as an adverb).
Lowercase the word as regardless of its function (even if using it as a pronoun or adverb).
Capitalize the first part of any hyphenated word. Follow other rules in determining whether the subsequent parts should be capitalized.
If the first part of a hyphenated word is a prefix or cannot otherwise stand alone as a word, then lowercase the second part unless it is a proper noun or proper adjective.
Examples of Title Capitalization in APA and Chicago Styles
Below are a few titles in both APA and Chicago Styles. The differences are highlighted with red type.
Peer Network Strategies to Foster Social Connections Among Adolescents With and Without Severe Disabilities (APA, capitalize prepositions longer than four words)
Peer Network Strategies to Foster Social Connections among Adolescents with and without Severe Disabilities (Chicago, lowercase all prepositions)
A Study of Mathematics Anxiety in Pre-Service Teachers (APA, capitalize both parts of a hyphenated word)
A Study of Mathematics Anxiety in Pre-service Teachers (Chicago, do not capitalize the second part of a hyphenated word if the first part cannot stand alone as a word)
“I’ll Join the Team if You Will”: Peer Pressure as a Factor in Youth Sports Participation (APA, lowercase conjunctions with fewer than four letters)
“I’ll Join the Team If You Will”: Peer Pressure as a Factor in Youth Sports Participation (Chicago, capitalize conjunctions except and, but, or, for, and nor)
Do you have questions about the capitalization of titles? Post them in the comments below.
The information for this post was drawn from the The Chicago Manual of Style (17th ed., sec. 8.159–61) and the Publication Manual of the American Psychological Association (7th ed., sec. 6.17). See these sources for more detailed guidance and examples.