capitol, capital

Capital or capital means main or most important, as in the capital city of a country or a capital letter--
The capital of the United States is Washington, D.C.
Always begin a sentence with a capital letter.

Capital punishment is the punishment for a capital, or most serious, crime--
The jury is being selected for a capital case.
Capital punishment means execution.

Capital also means a sum of money, particularly the money invested in a profit-making businesses--
He wanted to start a new business, but didn't have the capital.
Capitalism means using money to make money.

Capitol or capitol refers only to the building which is used as the seat of government--
The capitol is a tourist attraction.
The capitol took years to build.

Now that you know that, you can say--
"The capitol is in the capital."

Note--"Capital!" as an expression is old-fashioned British slang for "great!".
Note #2--Capitol Hill is where the U.S. Capitol stands. Washingtonians sometimes simply call it "the Hill".
Not to be confused with the Capitoline Hill, which is a particular place in Rome, on which its capitol once stood.