Style Guide Comparison
Compare capitalization rules across APA, MLA, Chicago, and AP style guides.
Quick Comparison Table
| Element | APA (7th Ed.) | MLA (9th Ed.) | Chicago (17th Ed.) | AP Style |
|---|---|---|---|---|
| Paper Titles | Title case | Title case | Title case (headline) | Title case |
| Section Headings | Title case (L1-L2), sentence case (L3-L5) | Title case or sentence case | Title case (headline) | Sentence case common |
| Reference List Titles | Sentence case (books, articles) | Title case | Title case | N/A (journalism) |
| Journal Names | Title case (italicized) | Title case (italicized) | Title case (italicized) | Title case |
| Prepositions | Lowercase (under 4 letters) | Lowercase | Lowercase | Lowercase (under 4 letters) |
| Conjunctions | Lowercase (under 4 letters) | Lowercase | Lowercase | Lowercase (under 4 letters) |
| Hyphenated Compounds | Capitalize both parts | Capitalize both parts | Capitalize first, varies for second | Capitalize both parts |
APA Style (7th Edition)
The American Psychological Association style is used primarily in social sciences, psychology, education, and nursing.
Title Case in APA
APA title case capitalizes:
- First word of the title/subtitle
- All major words (nouns, verbs, adjectives, adverbs)
- All words of four letters or more
- Both parts of hyphenated compounds
Keep lowercase:
- Short conjunctions (and, as, but, for, if, nor, or, so, yet)
- Short prepositions (at, by, for, in, of, off, on, per, to, up, via)
- Articles (a, an, the) unless first word
Sentence Case in APA
Used in reference list entries for article titles and book titles. Only capitalize:
- First word of title and subtitle
- Proper nouns
Example: "The development of social cognition in children" not "The Development of Social Cognition in Children"
MLA Style (9th Edition)
The Modern Language Association style is used in humanities, especially literature and language studies.
Title Case Throughout
MLA uses title case for almost all titles, including in Works Cited entries. This is simpler than APA's split approach.
MLA title case capitalizes:
- First and last words always
- Major words (nouns, pronouns, verbs, adjectives, adverbs, subordinating conjunctions)
Keep lowercase:
- Articles (a, an, the)
- Prepositions
- Coordinating conjunctions (and, but, for, nor, or, so, yet)
- The "to" in infinitives
Chicago Manual of Style (17th Edition)
Chicago style is used in publishing, history, and some social sciences. It offers both headline style and sentence style.
Headline Style (Title Case)
Chicago's headline style capitalizes:
- First and last words
- Major words
- Prepositions of five or more letters (about, above, beneath)
Keep lowercase:
- Articles (a, an, the)
- Short prepositions (four letters or fewer)
- Coordinating conjunctions
Sentence Style
Chicago sentence style follows standard sentence capitalization. Used in some bibliography styles and when a more casual tone is desired.
AP Style
The Associated Press Stylebook is used in journalism and news writing.
AP Headlines
AP uses title case for headlines with these rules:
- Capitalize first and last words
- Capitalize verbs, nouns, adjectives, adverbs
- Capitalize prepositions and conjunctions of four letters or more
Keep lowercase:
- Articles
- Short prepositions (three letters or fewer)
- Short conjunctions
Choosing the Right Style
Your choice of style guide depends on your field and audience:
- Academic psychology, education, nursing: APA
- Literature, languages, humanities: MLA
- History, publishing: Chicago
- Journalism, news: AP
When in doubt, ask your instructor, editor, or organization which style they require. Consistency within a document or publication matters more than which specific style you choose.
Using the Converter with Style Guides
Our Case Converter provides title case and sentence case conversions that work well as starting points for all major styles. For exact compliance:
- Convert to the appropriate base case (title or sentence)
- Review for style-specific rules about prepositions and conjunctions
- Adjust edge cases (hyphenated words, proper nouns) manually
This approach is much faster than manual formatting while still achieving accurate results.