Which sentence states a fact?
Rattlesnakes are the most dangerous reptiles. Rattlesnakes use their rattles to warn other animals.
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.
Rattlesnakes use their rattles to warn other animals.
It can be proved by looking up information about rattlesnakes.
The first sentence states an opinion.
Rattlesnakes are the most dangerous reptiles.
Most dangerous shows what a person believes, thinks, or feels. Another person might have a different opinion about which reptiles are the most dangerous.