Which sentence states a fact?
Harry Houdini, born Erich Weisz, used "Houdini" as his stage name to pay homage to famous French magician Robert Houdin. Harry Houdini was a mediocre magician, but many people considered him to be a skilled escape artist.
Statements of fact make claims that are based on research, observation, or experimentation. Facts can be proved with evidence.
Napoleon Bonaparte was shorter than King Louis XVI.
This statement is a fact. The statement can be verified by researching and comparing the height of each man.
Statements of opinion make claims that are based on personal judgments or perspectives. Opinions can be supported by evidence, but they cannot be definitively proved.
Napoleon Bonaparte was a better leader than King Louis XVI.
This statement is an opinion. People can have different ideas about what makes someone a "better" leader, so the statement cannot be proved.
The first sentence states a fact. It can be verified by looking up how Harry Houdini chose his stage name in a biography or Houdini's own writing.
Harry Houdini, born Erich Weisz, used "Houdini" as his stage name to pay homage to famous French magician Robert Houdin.
The second sentence states an opinion. Mediocre indicates a personal judgment.
Harry Houdini was a mediocre magician, but many people considered him to be a skilled escape artist.