Mistakes will always be made in French, and now you can learn from them.
Wrong: C'est une fait
Right: C'est un fait
Explanation: Fait (fact) is a masculine word, but it's pronounced just like fête (party), which is feminine. In writing, you can see the difference in spelling, but when speaking, c'est une fait sounds just like c'est une fête, meaning "it's a party," rather than "it's a fact."
I made this very mistake years ago during a classroom debate on euthanasia. Intending to say "death is a fact" (la mort est un fait), I instead said la mort est une fait (fête), which sounded, of course, like "death is a party." So you see, gender really does matter in French - et ça c'est un fait ! (And that's a fact!)
Related lessons:
French gender
Nouns with two genders

