So, you need to use title case, but you need to know what it is and how to do it. Well, that depends on who you ask. No matter which style guide you use, the basic principle is the same: The first word of the title and subtitle are uppercased, and major words have the first letter of the word capitalized. However, each style guide has its own requirements for how to use title case for that style.
Below you will see the guidelines compiled for APA, MLA, and Chicago/Turabian.
| Title Elements | APA 7th Edition | MLA 9th Edition | Chicago 17th Edition / Turabian 9th Edition |
| Name used within the style | Title case | Title-style capitalization | Headline-style capitalization |
| The first word of the title and subtitle | Uppercase | Uppercase | Uppercase |
| The first word after a colon | Uppercase | Uppercase | Uppercase |
| Major words (e.g. nouns, pronouns, verbs, etc.) | Uppercase | Uppercase (for titles in English; titles in other languages are sentence case) | Uppercase (for titles in English; titles in other languages are sentence case) |
| Last word | Uppercase only if it is a major word | Uppercase | Uppercase
(with one exception)1 |
| Articles (a, an, the) | Lowercase (unless it is the first word of the title or subtitle) | Lowercase
(unless it is the first word of the title or subtitle) |
Lowercase
(unless it is the first or last word in a title or subtitle) |
| Coordinating conjunctions | Lowercase if 3 or fewer letters (and, as, but, for, if, nor, or, so, yet)* | Lowercase
(and, but for, nor, or, so, yet)* |
Lowercase
(and, but, for, or, and nor unless used as the first or last word in a title or subtitle)* |
| Prepositions | If they are 3 letters or fewer, then lowercase them. (e.g. as, at, by, in, to, etc.) | Lowercase (e.g. according to, as, between, in) | Lowercase except when used as adverbs or as adjectives
“As” is lowercased no matter the part of speech. |
| “To” used as an infinitive | Lowercase | Lowercase | Lowercase
(unless it is the first or last word in a title or subtitle) |
| Other notes | A particle as part of a name is lowercased if it is normally lowercased in text. (von Trapp Family or Count de Saint-Germain) |
1. “Lowercase the second part of a species name, such as fulvescens in Acipenser fulvescens, even if it is the last word in a title or subtitle” (CMOS, p. 527, 8.159).
*Listed coordinating conjunctions are directly from their respective manuals. See below for attributions to each manual.