Definition · Plain-language
Capitalisation rules
Capitalisation rules govern when to write a word with an initial capital letter — required for proper nouns, the first word of a sentence, titles and acronyms, but not for seasons or general directions.
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Proper nouns and the first word of a sentence
The two most reliable capitalisation rules are also the most used. Every sentence begins with a capital letter. Proper nouns — words that name a specific person, place, organisation, day, month or holiday — are always capitalised: Maria, Paris, the United Nations, Wednesday, October, Ramadan. Common nouns (city, river, organisation) are lower case unless they form part of a proper name: the Thames (but "a river"), Oxford University (but "a university"). Capitalise official names and titles when they are part of the name itself: the National Health Service, the Treaty of Rome.
Titles, works and acronyms
Personal titles are capitalised immediately before a name (Dr Ahmed, President García, Professor Williams) but not when they appear after a name or are used generally (the president's speech; ask your professor). In titles of books, films, articles and artworks, capitalise the first word and all major words — nouns, verbs, adjectives and adverbs — while leaving articles, short prepositions and coordinating conjunctions in lower case, unless they open the title: "The Importance of Being Earnest"; "Pride and Prejudice". Acronyms and initialisations are typically written in full capitals: UNESCO, NHS, PDF, UK. Some well-established acronyms have become common nouns and are no longer capitalised: laser, radar, scuba.
What not to capitalise — common over-capitalisation errors
The seasons — spring, summer, autumn, winter — are common nouns in English and are lower case, unlike in German. Compass directions are lower case when describing direction (drive north, turn east) but capitalised when they are part of a proper noun or adjective (Northern Ireland, the Deep South, East Asia). The words government, parliament, and committee are lower case when used generically, though they may be capitalised when referring to a specific institution within formal or legal documents. After a colon, some style guides (especially American ones) capitalise the first word if a complete sentence follows; others keep it lower case. Whichever style you adopt, apply it consistently.
Key facts
At a glance
- First word: always capitalise the first word of every sentence
- Proper nouns: people, places, organisations, days, months and holidays
- Titles before names: Dr Smith, Professor Jones — but lower case after a name
- Acronyms: NASA, UNESCO, NHS — all caps; some absorbed into lower case (laser, radar)
- Titles of works: capitalise first word and major words (nouns, verbs, adjectives)
- Seasons: spring, summer, autumn, winter are lower case in English
- Directions: lower case for compass direction; capital when part of a proper name (Northern Ireland)
Common misconceptions
What people often get wrong
Often heard: Seasons should be capitalised because they are important time periods.
Actually: In English, the seasons (spring, summer, autumn, winter) are common nouns and are written in lower case. Only proper nouns and the first word of a sentence require a capital letter.
Often heard: Job titles should always be capitalised.
Actually: Titles are capitalised only when used directly before a name (Professor Okafor) or as part of a formal title. Used generically or after a name, they are lower case: "she is a professor"; "Richard Okafor, professor of physics".
Often heard: You should capitalise compass directions such as north, south, east and west.
Actually: Compass directions are lower case when they indicate direction (walk north; the wind came from the east). They are capitalised only when part of a proper noun or established regional name, such as Northern Ireland or the American South.
Going deeper
