Capitalization Rules: Words to Capitalize in a Sentence
Capitalize the first word of a sentence. Also capitalize proper nouns: names of people, places, organizations, departments, bridges, parks, buildings, and geographical features (oceans, mountains, deserts, etc.). But don’t capitalize words such as department and ocean when they are used as common nouns. Never capitalize a word merely for emphasis in formal writing.
Capitalization can be tricky. For example, words like mom are capitalized when used as a name or to address someone (Hi, Mom), but lowercased otherwise (my mom likes pizza). Similarly, titles like president are capitalized when used with a name or as a form of address (President Lincoln, Mr. President) but not otherwise (the president decides). Other commonly used words like sun and moon may be capitalized depending on how and where they are used. Often, it is simply a matter of accepted style (Table 5 but column 5).
Here is a quick but comprehensive guide to capitalization in English, in which we discuss generally accepted guidelines and some exceptions.
People, places, and companies
Capitalize names of people, places, and companies.
- I spoke to Anita over the phone yesterday.
- Nesbit and Rita have gone to Bali on holiday.
- It must be nice to have Tooksie back home from college.
- John F. Kennedy was assassinated in 1963 while traveling through Dallas, Texas, in an open-top Lincoln Continental convertible.
- All refrigerators made by General Electric simultaneously went sentient on October 7.
- It can get a little cold in Antarctica.
Countries
Capitalize the names of countries, but lowercase any articles (like the), prepositions (like of and in), and conjunctions (like and) that occur within the name.
- Much of the land area of the Netherlands consists of reclaimed land.
- Trinidad and Tobago lies on the continental shelf of South America, which is why its ecology is similar to that of Venezuela.
- One hundred fifty-six meteorites have been observed and recovered within the United States of America in the last 212 years.
An initial the in the name of a city is capitalized.
- One of my favorite cities in the Netherlands is The Hague.
Proper adjectives
Proper adjectives (adjectives derived from proper nouns) are usually capitalized as well.
- Lulu enjoys eating Italian food.
- Did you study Euclidean geometry in school?
- Many Dutch expatriates visit this hotel.
Regions and geographical features
Capitalize names of oceans, seas, continents, mountains, valleys, rivers, plains, deserts, plateaus, and other geographical features. These are all proper nouns, always capitalized in a sentence.
- The Pacific Ocean is the largest body of water in the world.
- How did we make the Aral Sea disappear?
- Numerous empires have risen and fallen in the fertile Indo-Gangetic Plain of Asia.
- Which is the longest river in the world—the Nile or the Amazon?
- They lived in a cabin beside Lake Hudson.
Note that generic terms such as river, sea, and mountain are capitalized when part of a name but lowercased otherwise.
- The River Nile is the longest river in the world.
- The Black Sea is a saltwater sea.
- The Rocky Mountains are a major mountain range in North America.
- The Hawaiian Islands are an archipelago of volcanic islands, atolls, and islets.
Also capitalize names of regions of the world.
- India is the largest country in South Asia.
- The territory of Siberia spans much of Eurasia and North Asia.
Buildings and structures
Capitalize names of specific buildings and structures such as bridges and monuments. If the word the precedes a name, lowercase it.
- The president of the United States lives in the White House.
- Have you seen the Bent Pyramid of Dahshur?
- Millions of tourists visit the Taj Mahal in Agra every year.
- The Yongji Bridge of Chengyang is one of the most beautiful bridges in the world.
- She lives in a white house with blue curtains.
- We lived in a cozy little apartment in sight of the Egyptian pyramids.
- Anita is an engineer who loves to build bridges.
Departments and organizations
Capitalize names of departments, ministries, institutions, and organizations. Lowercase an initial the when it falls within a sentence, and words such as of, for, and and that may form part of the name. (In short, lowercase articles, prepositions, and conjunctions.)
- The Department of Education has announced that schools shall no longer be needed.
- Nesbit received his master’s degree from the University of Nusquam in 2001.
- Anita is an assistant professor in the Department of Physics and Astronomy.
- The case of the missing lawnmower has been handed over to the Federal Bureau of Investigation.
- Doesn’t Poco work for the Ministry of Magic?
Don’t capitalize words like department and court when they are used as common nouns.
- Lulu is the best worker in the department.
- Nesbit went to university in Nusquam.
- Four posts have fallen vacant within the bureau.
Academic subjects
Lowercase names of school subjects such as physics, history, and biology.
- Ms. Scalene was my mathematics teacher in school.
- Maya studied philosophy in college.
- Nesbit is a physics major from Princeton.
But capitalize the names of languages, which are proper nouns.
- I am tired of teaching English literature to kids who steal all their assignments off the Internet.
- If I had taken Spanish instead of Latin in school, I would have been better prepared to travel the world.
If academic subjects form part of the name of a department, capitalize them.
- The Department of Philosophy is hosting a thought workshop today.
- It took her forty years to become head of the Department of Mathematics.
Time periods: Days, months, seasons, decades, centuries, eras, historical periods
Capitalize names of days and months. They are all proper nouns.
- We leave for Thailand on Tuesday.
- In January, the world seems renewed.
- It was on October 18 that the revolution finally began.
When a day of the week is pluralized, it is still capitalized.
- I love Saturdays!
- It took me a month of Sundays to finish reading this book.
Also capitalize names of holidays, festivals, and other special days (which are proper nouns).
- We met at a party on New Year’s Eve.
- Did you call your mom on Mother’s Day?
- Today is Veterans Day.
- We celebrate both Christmas and Hanukkah.
Lowercase names of seasons, unless used to denote a journal issue or a collection.
- The purple sneezeweed blooms in summer.
- All the trees danced with joy, glad that the long winter was finally over.
- The Fall 2021 issue of The Martian Literary Review is out in stores now.
Lowercase names of decades and centuries.
- She is a child of the nineties.
- The pandemic of the twenty-first century affected more people across more continents than any plague of the past.
The names of eras and historical periods are usually capitalized but not always. Terms that are merely descriptive are often lowercased.
- For women, the Renaissance was no different from any other period in history.
- Electricity had nothing to do with the Dark Ages being “dark.”
- These pieces of jewelry are from the early centuries of the Common Era.
- This school still uses colonial-era teaching methods.
- Some call this book the last great novel of the postmodern era.
Descriptive terms such as “postmodern” and “modern” may sometimes be capitalized in writing when used to refer to time periods or art movements, although lowercasing them is usually preferred. Follow a consistent style within a document.
Historical events
Capitalize the names of specific events in history.
- The Russian Revolution broke out before World War I was over.
- Nobody knows how many people died in the Massacre of Xuzhou.
- The Battle of Waterloo marked Napoleon’s final defeat.
- It will take a revolution to end this war.
- Hundreds of people were slaughtered in the massacre.
- A historic battle was fought on this field 200 years ago.
Celestial bodies
Names of galaxies, stars, planets, and other celestial bodies are generally capitalized.
- How far away from us is Alpha Centauri?
- For millennia, humans looked up in wonder at the Milky Way.
- We were guided on our travels by the North Star.
- Travelers to Neptune are advised to wear their space suits at all times to avoid freezing to death.
An exception is the “solar system,” which is usually lowercased. Also, the word earth, even when used to mean our planet, may be lowercased, especially when preceded by the word the.
- What on earth are you talking about?
- Some people still believe the earth is the center of the universe.
However, when used with names of other planets or in scientific writing, the word is capitalized.
- I would rather live on Venus than Earth.
- Here is a photograph of Earth as seen from space.
Similarly, the words sun and moon are not usually capitalized, except in scientific writing.
- “The Sun is a yellow dwarf star, a hot ball of glowing gases at the heart of our solar system.”
- The Moon is Earth’s only natural satellite.
- The sun and all the stars will fade away someday.
- All her crayons have melted in the sun.
- In the light of a gibbous moon, the princess crept toward the moonlit pond.
When used as common nouns (for example, in the plural), these words are always lowercased.
- There are seventy-nine known moons of Jupiter, none of which I have visited.
- Our new planet has two suns, so it’s always day wherever you are.
Nouns before numerals or letters
In general, capitalize nouns followed by numerals or letters that are part of a series.
- In Chapter 3, we discuss the importance of tea in the life of a human being.
- The routing graph is presented in Figure 4.
- For data collected in February, see Table 3.
- Here are the results of Experiment 9.
- I present to you Exhibit A, a screwdriver covered in blood.
- For a discussion on tea leaves specifically from Darjeeling, see Appendix C.
- She gave away the entire plot right in the first chapter of the book.
- Could you check whether the fourth figure on this page is correct?
- Pricing details are provided in an appendix to the report.
Words such as page, paragraph, line, stanza, row, and column are not usually capitalized, even when followed by a number.
- I am still on page 7 of this book.
- Please check the number in row 9, column 3.
When speaking about the parts of a book or a document, the general rule is that if a word can act as a heading, it is capitalized. Thus, while “Chapter 3” is capitalized, “page 3” isn’t. Similarly, “Table 5” should be capitalized, but “row 5” should not.
Nouns followed by numerals or letters that are not items in a numbered series but merely act as placeholders are generally lowercased.
- This car is no Ferrari, but it will take you from point A to point B.
- Let’s go with option 1 then.
Models, theories, and schools of thought
Do not capitalize the names of models and theories unless they contain proper nouns.
- The motivational theory we use is Maslow’s hierarchy of needs.
- The competitive strength of an organization can be assessed using Porter’s five forces model.
- A brand positioning map can help you understand how consumers perceive your brand in comparison to others.
- Psychologists have finally proven Freud’s repressed memory theory.
- Only the privileged can speak blithely of existentialism.
- We used the differential equation model to compare the two sets of data.
- Albert Einstein is famous not just for his hairdo but also his general theory of relativity.
Schools of thought and philosophical approaches are sometimes capitalized (e.g., Existentialism), although most style manuals recommend lowercasing them. Such questions of capitalization are a matter of style rather than grammar. Follow a consistent style within a document.
Diseases and disorders
Don’t capitalize the names of diseases, conditions, and disorders.
- Diseases such as malaria and cholera can be prevented by taking certain precautions.
- I wasn’t in at work last week because I had the flu.
- She was diagnosed with postpartum depression but insisted it was merely a case of acute nihilism.
However, do capitalize any proper nouns that form part of the name.
- Studies show that estrogen may slow the progress of Alzheimer’s disease.
- Farley was about five years old when symptoms of Duchenne muscular dystrophy began to appear.
Species
Do not capitalize the common names of species.
- There are fewer than four thousand tigers left in the world.
- The tiger is the largest member of the cat family.
- The spur-winged goose lives on a diet of blister beetles, which makes this goose poisonous to predators.
Proper adjectives that form part of the name are capitalized.
- The Egyptian goose is native to Africa.
- The Tasmanian tiger went extinct in 1936.
Latin names of species are italicized. Capitalize the genus, and lowercase the species name (even if it is a proper adjective).
- The Mangifera indica, or the mango, is native to the Indian subcontinent.
- The Chinese mountain cat belongs to the genus Felis.
Directions
Lowercase words such as east and west (and derivative words such as eastern) when referring to direction or location.
- Wheat is grown in the western region of the country.
- We went up a narrow road north into the mountains.
Capitalize the names of regions and places.
- Uruguay is a beautiful country in South America.
- Baltimore is a major city in the Northeast.
For more examples, see this article on capitalizing names of directions and compass points.
Official titles
Capitalize official titles when used before a person’s name or in place of it.
- Lulu interviewed President Clinton in 1999.
- Early this morning, Vice Chancellor Wang announced her resignation.
- We invited Premier Johnson to watch the launch of the space shuttle.
- Fortunately, Deputy Prime Minister Femy will not be present.
- Four former presidents attended the funeral.
- When will Anita be promoted from vice chancellor to chancellor?
- We went to hear the premier speak in Ontario.
- Who knows what the duties are of a deputy prime minister?
For more examples, see this article on capitalizing civil and official titles.
Kinship terms
Lowercase words such as “mom” and “dad” when you use them as common nouns.
- My dad likes to tell the strangest jokes.
- My mother’s childhood photographs smell of the past.
- Maya’s aunt is an astronaut and a scientist.
But capitalize familial terms used as a name or before a name.
- I wonder why Mom and Dad haven’t called me yet.
- Please, Mother, try to understand!
- Lulu visited Grandpa last week.
- I hope Aunt Lily enjoys her trip to Mars.
For more examples, see this article on when to capitalize family titles.
Titles and headings
Titles and headings may be capitalized using either title case or sentence case. Various style guides prescribe different rules. In general, in title case, the first and last words and all words except articles (a, an, the), prepositions (of, in, on, at, etc.), and conjunctions (and, or, but, etc.) are capitalized.
- The Unbearable Lightness of Being
- To the Lighthouse
- Stranger in a Strange Land
- The Book of Laughter and Forgetting
In title case, capitalize all forms of the be verb (is, are, were, etc.).
- How to Be an Antiracist
- Eleanor Oliphant Is Completely Fine
- When We Were Orphans
In sentence case, only the first word and all proper nouns are capitalized.
- A pair of blue eyes
- Jane Eyre
- The truth about Mary
For more examples, including how to capitalize hyphenated terms, see Title Case: Words to Capitalize in Titles, Headings, and Headlines.