Which sentence states a fact?
Willis Tower ruins the beauty of Chicago's downtown. Chicago's Willis Tower stands 1,450 feet tall.
A fact is something that can be proved to be true.
The month of July has more days than the month of June.
This is a fact. It can be proved by looking at a calendar and counting the number of days in each month.
An opinion is something that a person believes, thinks, or feels. An opinion cannot be proved true.
July is a better month than June for camping.
This is an opinion. People may have different opinions about which month is "better" for camping.
The second sentence states a fact.
Chicago's Willis Tower stands 1,450 feet tall.
It can be proved by checking a website about Willis Tower.
The first sentence states an opinion.
Willis Tower ruins the beauty of Chicago's downtown.
Ruins the beauty shows what a person believes, thinks, or feels. Another person might have a different opinion about whether Willis Tower makes Chicago less beautiful.