“To” is normally lowercase in the middle of titles under APA, Chicago, and MLA-style capitalization when it functions as a short preposition; Chicago also explicitly keeps “to” lowercase as an infinitive marker in ordinary mid-title position. Edge position can change the result.
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Quick answer
Usually no in the middle of a title. “To” is a two-letter preposition in many titles, and Chicago also keeps the infinitive marker “to” lowercase internally. Capitalize it when it is the first or, where the chosen style requires it, the last word.
Key details
Chicago 18 Infinitivelowercase internally
Converter Noteposition and style must be evaluated before conversion
Normal Mid Title Formto
Termto
Word Classpreposition or infinitive marker
Further guidance
As A Preposition
As a short internal preposition, “to” remains lowercase under APA’s short-minor-word rule and Chicago 18’s four-or-fewer-letter preposition rule. MLA editorial guidance likewise lowercases internal prepositions.
As An Infinitive Marker
Chicago specifically says the infinitive marker “to” remains lowercase in ordinary mid-title position, as in “Born to Run.”
Edge Positions
Chicago capitalizes the first and last word regardless of syntax. MLA’s current ninth-edition public guidance also identifies first and last words as capitalized.
Practical Rule
A robust converter must distinguish position and style before changing the token. This guide does not use a global “always lowercase to” rule.
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.
“Of” is normally lowercase in the middle of a title in APA 7, Chicago 18, and MLA-style title capitalization because it is a short preposition. First- or last-word position can override the ordinary middle-of-title treatment.
Prepositions are one of the clearest places where title styles diverge. APA uses a four-letter major-word threshold, Chicago 18 capitalizes prepositions of five letters or more, and MLA editorial guidance generally lowercases internal prepositions regardless of length.
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.
