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.”
ReviewedEvidence2 sourcesSectionWriting & Style
Quick answer
Do not use one universal “FANBOYS” rule for every title style. APA 7 lowercases short conjunctions of three letters or fewer in ordinary mid-title positions. Chicago 18 lowercases and, but, for, or, and nor, while “so” and “yet” are capitalized. Edge-position rules can override the normal middle-of-title treatment.
Key details
Apa 7 RuleShort conjunctions of three letters or fewer are normally lowercase mid-title
Chicago 18 Lowercase Setand, but, for, or, nor
Important DifferenceChicago 18 capitalizes so and yet where a blanket seven-conjunction rule would not
Rule Familyminor-words
Style-by-style guidance
APA 7
APA groups short conjunctions of three letters or fewer with other minor words. In an ordinary mid-title position, this makes and, as, but, for, if, nor, or, so, and yet lowercase unless another APA capitalization rule applies.
Chicago 18
Chicago 18 identifies five common coordinating conjunctions for lowercase treatment in ordinary mid-title positions: and, but, for, or, and nor. Current Chicago guidance therefore does not treat “so” and “yet” the same way as those five.
Further guidance
Practical Rule
Choose the required style before converting a title. A generic converter that lowercases all seven coordinating conjunctions can disagree with current Chicago on “so” and “yet,” while a converter that capitalizes every short word can disagree with APA.
Why Styles Disagree
Title case is a style convention, not one universal grammar rule. Two guides can classify the same conjunction differently for capitalization even though its grammatical function has not changed.
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.
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.
“As” is a grammar-sensitive title-case word. APA normally lowercases it internally because it is a short conjunction or preposition, while Chicago 18 explicitly keeps “as” lowercase in any grammatical function except where a boundary rule independently requires capitalization.
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.
“For” is normally lowercase in the middle of both APA and Chicago title case when it functions as a short conjunction or short preposition. Position still matters, and a converter should not generalize that answer to unrelated grammatical uses without checking context.
APA normally lowercases the short conjunction “if” internally, while Chicago capitalizes subordinating conjunctions such as “If.” This is a genuine cross-style difference, so the requested style matters. This guide separates style-specific treatment instead of using one universal small-word 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.
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.
“So” is normally lowercase in the middle of APA and Chicago title case when it functions as one of the short/common coordinating conjunctions covered by those styles. It is capitalized when a positional rule applies, such as appearing first in the title.
