Vocabulary
B1–B2
5 min read
Updated 10 June 2026
Quick answer: Capital (ending in -al) has several meanings: a capital city (Paris is the capital of France), an uppercase letter (Write your name in capitals), or money/wealth (venture capital). Capitol (ending in -ol) refers specifically to a building where a legislature meets — most famously the US Capitol in Washington, D.C. Memory trick: a capItOl is a dOme-shaped building (O for the dome).
Comparison Table
| Word | Part of Speech | Meaning | Example |
|---|
| capital | noun / adjective | a seat-of-government city; uppercase letter; money/wealth; most important | London is the capital of England. |
| capitol | noun | a building where a legislature meets (especially the US Capitol) | The senators met at the Capitol. |
Using Capital
Capital is the far more common and versatile word. It appears across politics, finance, grammar, and general usage:
Tokyo is the capital city of Japan.
Always begin a sentence with a capital letter.
The company raised capital to fund its expansion.
Murder is a capital offence in some countries. (adjective: punishable by death)
Key Uses of Capital
- Political geography: The capital of Australia is Canberra, not Sydney.
- Typography: Write your surname in capitals.
- Finance: capital investment, venture capital, working capital
- Adjective (most important): of capital importance
- Adjective (death penalty): capital punishment, capital crime
Using Capitol
Capitol is a much narrower term. In the United States, the Capitol (always capitalised) is the building in Washington, D.C., where Congress meets. With a lowercase c, capitol refers to any building where a state legislature convenes.
Congress convenes in the Capitol Building.
The protesters marched to the state capitol.
The dome of the Capitol is an iconic landmark.
Outside of the United States, capitol is rarely used. In British English, capital covers all political-geography uses, and the buildings where Parliament meets are called the Houses of Parliament or the Palace of Westminster — never a capitol.
Memory Trick
The letter O is key: capitOl ends in O — picture the Oval dome on top of the Capitol building. capitAl ends in A — think of A city, A letter, or A mount of money. The saying: The O in capitOl stands for the dOme.
Common Mistakes
Mistake 1 — Using capitol for a capital city
✗ Berlin is the capitol of Germany.
✓ Berlin is the capital of Germany.
Mistake 2 — Using capital for the US government building
✗ They stormed the US Capital building.
✓ They stormed the US Capitol building.
Mistake 3 — Writing "capital city" with an O
✗ What is the capitol city of Canada?
✓ What is the capital city of Canada?
Mini-Quiz
Test your understanding with an interactive exercise:
Frequently Asked Questions
What is the difference between capital and capitol?
Capital (ending in -al) has many meanings: a seat-of-government city (Paris is the capital of France), an uppercase letter (write in capitals), or money and wealth (venture capital). Capitol (ending in -ol) specifically refers to a building where a legislature meets — primarily the US Capitol in Washington, D.C. For almost all everyday uses outside of discussing the US Congress building, you need capital.
When should I use capitol with an O?
Use capitol (with an O) only when referring to a building where a legislature meets. In the United States, the Capitol (always capitalised) is the building in Washington, D.C., where Congress meets. With a lowercase c, capitol refers to any US state legislature building. Outside the United States, the word capitol is rarely used — British, Australian, and other Anglophone writers almost always use capital instead.
Is Washington, D.C. a capital or a capitol?
Washington, D.C. is a capital — it is the capital city of the United States. The Capitol (with an O) is a specific building in Washington, D.C., where Congress meets. So: Washington, D.C. is the capital (city); the Capitol is a building within Washington, D.C. The city uses capital; the building uses capitol.
What does capital mean in finance?
In finance, capital refers to money or assets used to start or run a business, or wealth that can be invested or deployed. Key phrases: venture capital (money invested in start-up companies), working capital (funds available for day-to-day operations), capital gains (profit from selling an asset), capital investment (money spent on long-term assets), and capital market (where long-term financial instruments are traded). Capitol is never used in financial contexts.
What is capital punishment?
Capital punishment is the legal execution of a person as punishment for a crime — also called the death penalty. Capital here is an adjective meaning involving or punishable by death, derived from the Latin caput (head), since execution historically involved beheading. A capital crime or capital offence is one that carries the death penalty. Note that the spelling is capital, not capitol — this use has nothing to do with government buildings.
Does the UK use the word capitol?
Rarely. In British English, capitol is almost exclusively used when referring to the US Capitol building. British writers would not call the Houses of Parliament a "capitol." For all purposes — city, letter, or money — British English uses capital. The confusion between capital and capitol is primarily a challenge for learners studying American English or writing about US politics.
How do I remember capital vs capitol?
The O in capitOl stands for the dOme of the Capitol building — picture the rounded dome on the US Capitol and let that O remind you of the spelling. CapitAl ends in A — think of A city, A letter, A mount of money. Another trick: capitol refers to a very specific building; capital refers to almost everything else. If in doubt, use capital — you will be right 95% of the time.
What is capital in the context of grammar?
In grammar, a capital letter (or capital) is an uppercase letter — A, B, C rather than a, b, c. Rules for capitalisation include: start every sentence with a capital letter; capitalise proper nouns (names of people, places, organisations); capitalise the pronoun I; capitalise the first word of a direct quote. In British English, "writing in capitals" means writing in uppercase; "block capitals" means all uppercase letters used for forms and documents.
Are there capitols outside the United States?
The word capitol is primarily an American English term. In other countries, the buildings where legislatures meet have their own names: Houses of Parliament (UK), Bundestag (Germany), National Assembly, Parliament Building, and so on. When writing in British English or international English about foreign government buildings, the word capital (or the building's specific name) is used rather than capitol. In American English, capitol (lowercase) can technically refer to any legislative building, but this usage is uncommon outside the US context.
What is "human capital"?
Human capital is an economic concept referring to the skills, knowledge, education, and experience of people — treated as a productive resource, like financial or physical capital. The idea is that investing in education and training increases a person's (or workforce's) economic value. Example: "The company invested heavily in human capital through training programmes." This is a capital (not capitol) usage, connected to the economic/financial sense of capital as a productive asset.