Which sentence states a fact?
Alexander Graham Bell invented the electric telephone in the 1870s. The telephone was the greatest invention of its time.
A fact is something that can be proved to be true. Facts can be proved by observing, measuring, or studying information.
The flag of the United States has 13 stripes.
This is a fact. It can be proved by looking at the flag and counting the number of stripes.
An opinion is something that a person believes, thinks, or feels. An opinion cannot be proved true.
The flag of the United States is easy to draw.
This is an opinion. People may have different opinions about what makes a flag "easy" to draw.
The first sentence states a fact.
Alexander Graham Bell invented the electric telephone in the 1870 s.
It can be proved by reading a book about Alexander Graham Bell.
The second sentence states an opinion.
The telephone was the greatest invention of its time.
Greatest shows what a person believes, thinks, or feels. Another person might have a different opinion about what the greatest invention was.