capitol, capital, capital (money)

  edgood  —  Grammar Tips
The word capitol should be used only to describe an actual governmental building. (My fourth-grade teacher taught us that the building is spelled with an “o” as in “dome,” something that most capitols have on their roofs.)

Capital has many meanings as both a noun and an adjective. As a noun, capital means “a city where the center of government resides,” or it can refer to money. As an adjective, capital can describe something very good (a capital idea) or something not so good (a capital crime).

Capitol has only one meaning, a building.

Also, the word Capitol begins with a capital letter only when referring to the building where the United States Congress meets. But on state-government websites, you’ll find the capitalized Capital to refer to their state capital (the city).

Example: The dome of the capitol building can be seen from anywhere in the capital city. Officials in the state capital plan to raise additional capital for needed renovations of the capitol.