Text & writing
What Is Sentence Case? Rules and Examples
Sentence case capitalizes text the way an ordinary sentence is capitalized: the first word and proper nouns get capitals, and everything else is lowercase. It is the default for running text and an increasingly common choice for headings and titles. This guide covers the rules, the tricky cases, and where sentence case is required.
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The rules
Example: “The Quick Guide To Working With Excel In London” becomes “The quick guide to working with Excel in London”. Excel and London stay capitalized because they are proper nouns.
- Capitalize the first word of the sentence, heading, or title.
- Capitalize proper nouns: names of people, places, organizations, brands, and products.
- Capitalize the pronoun “I” and acronyms such as NASA or UK.
- Keep every other word lowercase, including long or important-looking words.
Where sentence case is required
Other styles make different choices — AP, APA, Chicago, and MLA all use title case in some contexts — so the requirement depends on the style you are following.
- APA Style uses sentence case for the titles of articles, books, reports, webpages, and other works in reference lists.
- The UK government’s GOV.UK style guide says to always use sentence case, even in page titles and service names.
- Many software interfaces and design systems use sentence case for buttons, menus, and headings.
Tricky cases
- Proper nouns inside titles are the most common mistake: automated sentence-case conversion cannot tell “apple” the fruit from “Apple” the company, so names need a manual check.
- Words after a colon: some styles capitalize the first word after a colon in a title and others do not — follow your style guide.
- Brand names with unusual capitalization (iPhone, eBay) keep their own styling.
- Headings that are questions or commands still follow the same rule: only the first word and proper nouns are capitalized.
Why many writers prefer it for headings
Sentence case has fewer rules than title case, so it is applied more consistently across a team. It reads like normal text, and proper nouns stand out because they are the only capitalized words after the first.
What Is Sentence Case? FAQ
- What is sentence case?
- A capitalization style where only the first word and proper nouns start with a capital letter, as in an ordinary sentence.
- Do proper nouns stay capitalized in sentence case?
- Yes. Names of people, places, organizations, and products keep their capitals.
- Does APA use sentence case?
- Yes, for the titles of works in reference list entries — articles, books, reports, webpages, and more.
- Is sentence case correct for email subject lines?
- It is a common and perfectly acceptable choice. Consistency within an organization matters more than which style is used.
- Why did a converter lowercase a name in my title?
- Automatic sentence case cannot reliably tell which ordinary-looking words are names. Check proper nouns after converting and re-capitalize them.
Related guides
- Uppercase vs. Lowercase vs. Title CaseWhat uppercase, lowercase, title case, and sentence case are, where the terms come from, where each is conventionally used, and how to choose a style for headings.
- Title Case RulesWhich words to capitalize in a title, how AP, APA, Chicago (18th edition), and MLA differ on prepositions and conjunctions, and one title shown in all four styles.
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