Which sentence states a fact?
The prettiest parts of the Rocky Mountains are in the state of Wyoming. In the United States, the Rocky Mountains stretch from New Mexico to Montana.
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.
In the United States, the Rocky Mountains stretch from New Mexico to Montana.
It can be proved by checking a map of the United States.
The first sentence states an opinion.
The prettiest parts of the Rocky Mountains are in the state of Wyoming.
Prettiest shows what a person believes, thinks, or feels. Another person might have a different opinion about where the prettiest parts of the Rocky Mountains are.