Usually no in the middle of a title. APA lowercases the short conjunction “or,” Chicago 18 explicitly includes “or” in its lowercase coordinating-conjunction set, and MLA title style normally keeps coordinating conjunctions lowercase internally. The answer depends on the style guide and position, so this page separates APA 7, Chicago 18, and MLA guidance instead of applying one generic title-case list.
ReviewedEvidence4 sourcesSectionWriting & Style
Quick answer
Usually no in the middle of a title. APA lowercases the short conjunction “or,” Chicago 18 explicitly includes “or” in its lowercase coordinating-conjunction set, and MLA title style normally keeps coordinating conjunctions lowercase internally.
Key details
APA 7Lowercase in ordinary mid-title position as a short conjunction
Chicago 18Lowercase in ordinary mid-title position as a named common coordinating conjunction
MLA 9Normally lowercase internally under the principal-word/minor-word convention; first and last words are capitalized
Normal Mid Title Formor
Termor
Word Classcoordinating conjunction
Style-by-style guidance
APA 7
Lowercase in ordinary mid-title position as a short conjunction.
Chicago 18
Lowercase in ordinary mid-title position as a named common coordinating conjunction.
MLA 9
Normally lowercase internally under the principal-word/minor-word convention; first and last words are capitalized.
Important caveats
Boundary Note
First-position rules, subtitle starts, and style-specific last-word rules can override the ordinary middle-of-title treatment. Always identify the requested style before applying a small-word rule.
Further guidance
Quick rule
Usually no in the middle of a title. APA lowercases the short conjunction “or,” Chicago 18 explicitly includes “or” in its lowercase coordinating-conjunction set, and MLA title style normally keeps coordinating conjunctions lowercase internally.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
APA title case capitalizes the first word, the first word of a subtitle, major words, and words of four letters or more while keeping short minor words lowercase in ordinary mid-title positions.
Chicago 18 uses title case for titles of works and changed a long-standing rule: prepositions of five letters or more are now capitalized. Shorter prepositions generally remain lowercase internally, while first and last words are capitalized and “to” remains lowercase as an infinitive marker in ordinary mid-title use.
Coordinating conjunctions are a major source of title-case differences: APA lowercases short conjunctions, while current Chicago names a narrower lowercase set and capitalizes “so” and “yet.”
MLA 9 describes title style as capitalizing the first word, last word, and all principal words. MLA’s public Style Center also documents the traditional lowercase treatment of internal prepositions, but its detailed preposition article is edition-labeled for MLA 8, so this engine does not yet treat the full MLA 9 converter profile as complete.
The word “and” is normally lowercase in the middle of a title because it is a coordinating conjunction, but first-word, last-word, and style-specific rules can change the answer.
Usually no in the middle of a title. APA lowercases short conjunctions such as “but,” Chicago 18 explicitly lowercases “but” among its common coordinating conjunctions, and MLA title style normally leaves coordinating conjunctions lowercase unless a boundary rule applies. The answer depends on the style guide and position, so this page separates APA 7, Chicago 18, and MLA guidance instead of applying one generic title-case list.
Usually no in the middle of a title. APA treats the short conjunction “nor” as a minor word, Chicago 18 names “nor” among the coordinating conjunctions it lowercases, and MLA title style normally leaves coordinating conjunctions lowercase internally. The answer depends on the style guide and position, so this page separates APA 7, Chicago 18, and MLA guidance instead of applying one generic title-case list.
APA capitalizes “About” internally because it has at least four letters. Chicago 18 also capitalizes it when used as a preposition because current Chicago capitalizes prepositions of five letters or more. MLA treatment still depends on grammatical function, so prepositional and principal-word uses should not be collapsed into one rule.
