Which sentence states a fact?
The plastic toothbrush was one of the most brilliant inventions in the history of the world. Centuries ago, the Chinese invented the toothbrush by attaching pig hairs to a bamboo handle.
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 second sentence states a fact.
Centuries ago, the Chinese invented the toothbrush by attaching pig hairs to a bamboo handle.
It can be proved by looking up the history of toothbrushes.
The first sentence states an opinion.
The plastic toothbrush was one of the most brilliant inventions in the history of the world.
Most brilliant shows what a person believes, thinks, or feels. Another person might have a different opinion about whether the toothbrush was a brilliant invention.