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.
ReviewedEvidence4 sourcesSectionWriting & Style
Quick answer
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.
Key details
APA 7Lowercase internally as a short conjunction
Automation NoteBoundary rules can override ordinary internal treatment; abbreviations and ambiguous syntax may require review.
Chicago 18Capitalize as a subordinating conjunction
MLA 9Treat as a principal word under current headline-style guidance; automation requires manual review pending the complete current minor-word matrix
TermIf
Word Classsubordinating conjunction
Style-by-style guidance
APA 7
Lowercase internally as a short conjunction.
Chicago 18
Capitalize as a subordinating conjunction.
MLA 9
Treat as a principal word under current headline-style guidance; automation requires manual review pending the complete current minor-word matrix.
Important caveats
Automation boundary
When token form, syntax, or preserved casing cannot be established safely, leave the case unresolved rather than guessing.
Further guidance
Quick rule
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.
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.
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.
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.
APA capitalizes “Across” 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.
APA capitalizes “After” 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.
APA capitalizes “Against” internally because it has at least four letters. Chicago 18 also capitalizes it because prepositions of five letters or more are capitalized. MLA ordinarily lowercases internal prepositions, while any principal-word use needs grammatical classification before an automated decision.
APA capitalizes “Among” internally because it has at least four letters. Chicago 18 also capitalizes it because prepositions of five letters or more are capitalized. MLA ordinarily lowercases internal prepositions, while any principal-word use needs grammatical classification before an automated decision.
