Which spelling is correct? Learn the difference between "certainty" and "certainity". These are commonly confused spellings and how to use them correctly.
Incorrect spelling - No official definition exists—this is a misspelling of certainty.
"Certainity" is a common misspelling of "Certainty". Always use "Certainty" when referring to the correct word.
Correct spelling - The proper way to spell this word.
A state of being completely confident or sure about something; the quality of being certain.
"Certainty": A state of being completely confident or sure about something; the quality of being certain.
This word is commonly used in everyday conversation and writing.
"Correct:" There is a certainty that the sun will rise tomorrow.
"Correct:" She spoke with certainty about the results of the experiment.
"Correct:" Winning the championship is not a certainty, but they have a good chance.
"Correct:" The doctor treated the patient with the certainty that the procedure would succeed.
"Incorrect:" There is a certainity that he will arrive on time.
"Incorrect:" I can’t speak with certainity about the outcome.
"Incorrect:" Success is not a certainity, but we hope for it.
"Incorrect:" She answered the question with certainity.
A1: No. “Certainity” is always a misspelling. Use certainty.
A2: Think of the root word “certain” + -ty → certainty.
A3: Both! It can refer to absolute facts (“the certainty of gravity”) or confidence in beliefs (“she spoke with certainty”).
A4: Rarely, but yes: “There are several certainties in life, like death and taxes.”
Certainty is the correct spelling for being completely sure. Certainity is a misspelling and should not be used in any context.