Capital letters have been in decline for centuries and, with the advent of email and text messaging, they are becoming an endangered species.
They are no longer used is some referencing systems to initialise the titles of articles and books; The Guardian has abandoned them in offices
of state, prestigious job titles and geographical regions (prime minister, home secretary, chief executive, personnel manager, the north-east,
central America); they are disappearing from place-name adjectives (cheddar cheese, french windows, yorkshire pudding); and acronyms,
especially in newspapers, are now written with only their initials capitalised (Acas and Nato, rather than ACAS and NATO).
In view of these developments, the best we can do is set out the circumstances in which capitals are traditionally required in formal English and
then make our own decisions about how scrupulously we want to follow the rules.
Capital letters, then, are used to write the personal pronoun I and to begin sentences and direct speech: The chairman cleared his throat and said,
'Good morning'. Their additional uses are as follows.
Names and Eponyms
People's names take capital initials (Michael Jones, Mary Smith), as do their appellations (Mr, Ms, Mrs, Miss, Rev, Dr, Prof), but the capitalisation
of eponyms (words derived from people's names) is less consistent. Most take lower case –
nicotine (Jean Nicot)
ohm (Georg Simon Ohm)
sadist (Marquis de Sade)
sandwich (the 4th Earl of Sandwich)
saxophone (Antoine Sax)
volt (Alessandro Volt)
watt (James Watt)
A few still appear in upper case, but the trend is changing –
Braille or braille (Louis Braille)
Caesarean section or caesarean section (Julius Caesar)
Morse code or morse code (Samuel Morse)
Adjectives, and nouns ending in -ism, generally take upper case –
Platonic, Platonism (in reference to Plato's philosophy); platonic (in reference to a non-sexual friendship)
but occasionally –
and always –
masochistic, masochism (Leopold von Sacher-Masoch)
spooneristic, spoonerism (Revd W. A. Spooner)
Abbreviations of more than one word are fully capitalised with no separating points (TUC, CBI, EU). One-word abbreviations (dept, govt) take lower
case but should be written in full in formal English. The point is omitted if the last letter is the same as it would be in the full word: no. for 'number'
(different last letters so a point is added); nos for 'numbers' (same last letters so no point is added). Acronyms (abbreviations pronounced as words)
are fully capitalised if they are proper noun –
Otherwise, they are written in lower case –
laser (light amplification by stimulated emission of radiation)
radar (radio detection and ranging)
scuba (self-contained underwater breathing apparatus)
• titles of dignitaries and offices of state: Prime Minister, Lord Chief Justice, Archbishop of Canterbury; but not if the post is unspecific: a
prime minister, a lord, an archbishop
• continents, countries, cities, streets, etc.: Asia, Asian, Russia, Russian, South Glamorgan, Bristol, Oxford Street
• rivers, mountains, oceans, deserts, etc.: River Thames, Mount Everest, Atlantic Ocean, Sahara Desert
• ships: Queen Mary, Ark Royal
• businesses and institutions: Ford Motor Company, Church of England, Joe's Ice Cream Parlour, Grand Hotel, Jesus College, National
• days and months: Monday, Tuesday, January, February
• celestial bodies: Jupiter, Sirius, Milky Way. Curiously, capitalisation is optional with the Earth (earth), the Moon (moon) and the Sun (sun).
• significant historical events: Second World War, Norman Conquest, Magna Carta, Fifth of November, September Eleven
• religious festivals: Christmas, Ramadan
• titles of newspapers, books, films, plays and works of art: The Daily Mirror, Pride and Prejudice, The Mill on the Floss, The French
Connection, An Inspector Calls, Guernica. Note that articles, conjunctions and prepositions take lower case unless they begin the title (see
also italics and quotation marks)
• God or Allah and His pronouns, whether we believe in Him or not. But the polytheistic god takes lower case, as do metaphorical uses of the
word such as He made a god of money, or a goddess of the silver screen
• single-letter prefixes: T-shirt, U-Turn, X-Ray, but e-mail (usually now email)
Seasons and compass points take lower case (autumn, spring, north east), as do academic subjects (economics, history, philosophy, physics)
unless they are languages or awards (English, BA History).