Anytime you write a city and state or a city and country together in a sentence, you must separate them with a comma.
This summer, we visited Boston, Massachusetts.
I attend college in Evanston, Illinois.
My brother studied abroad in Vienna, Austria.
Add a second comma, after the state or country, if the sentence continues.
We visited Boston, Massachusetts, this summer.
The university in Evanston, Illinois, offers a summer high school program.
The soccer team in Barcelona, Spain, is very competitive.
Always place a comma between a city and a state and between a city and a country. Place a second comma after the state or the country if the sentence continues.
It’s your turn. Where in this sentence should you place a comma? The Nobel Peace Prize is awarded each year in Oslo Norway. Did you put a comma between the city and the country? Good for you!