The Rules of Title Capitalization
Title case (also known as headline style) is the standard convention used for capitalizing the titles of published works, blog articles, research papers, movies, and press releases. Unlike sentence case (where only the first word and proper nouns are capitalized), title capitalization mandates that all major grammatical words (nouns, pronouns, verbs, adjectives, and adverbs) start with a capital letter, while short function words (articles, coordinating conjunctions, and prepositions) remain in lowercase.
However, different academic and journalistic style manuals enforce subtle, conflicting rules regarding prepositions, hyphenated words, and subordinating conjunctions. Understanding these distinctions is critical for publishers, students, copywriters, and content strategists.
APA 7th Edition (Academic & Scientific)
Standardized by the American Psychological Association:
- Capitalize the first word of the title and subtitle (after a colon or dash).
- Capitalize all words of 4 letters or more (including prepositions like
With, From, Over, Into). - Lowercase conjunctions and prepositions of 3 letters or fewer (
and, but, for, in, on, at, to).
Chicago Manual of Style (CMOS 17th)
Standard for book publishing, historical essays, and fine arts:
- Lowercase all prepositions regardless of length (e.g.,
between, through, without, against). - Lowercase the articles (
a, an, the) and coordinating conjunctions (and, but, for, or, nor). - Lowercase the word
towhether used as a preposition or as an infinitive marker.
Comparison Matrix: Major Style Guide Differences
| Style Manual | Treatment of Long Prepositions (e.g., "Through", "Between") | Hyphenated Words | Subtitles (Post-Colon) |
|---|---|---|---|
| APA 7th Edition | Capitalized (≥ 4 letters) | Both elements capitalized if ≥ 4 letters | Always capitalized |
| Chicago (CMOS) | Lowercased (regardless of length) | Both elements capitalized unless minor word | Always capitalized |
| MLA 9th Edition | Lowercased (regardless of length) | Second element lowercased if it is a minor word | Always capitalized |
| AP Stylebook | Capitalized (≥ 4 letters) | Both elements capitalized if ≥ 4 letters | Always capitalized |
Frequently Asked Questions
Why is the verb "Is" capitalized in title case?
Even though is, am, are, was, and be are short words (2–3 characters), they are verbs. In all major style guides (APA, Chicago, MLA, AP), all verbs—regardless of length—are major parts of speech and must always be capitalized.
How are words after colons or em-dashes handled?
Under APA, Chicago, and MLA conventions, the first word of a subtitle immediately following a colon (:), question mark (?), exclamation mark (!), or em-dash (—) is always capitalized, even if that word is normally a minor word like the, an, in.
Does this converter preserve acronyms like API, NASA, or SQL?
Yes. When the "Preserve Existing Acronyms" checkbox is enabled, uppercase abbreviations and initialisms are retained without forcing them into lowercased letters.
