Early in the Captain Marvel movie, Carol Danvers (going by the name ‘Vers’) crashes to earth and fights off a Skrull attack, thus convincing the young(ish) Nick Fury that she is not from Earth. Skrulls are shapeshifters, and Fury sees one transform back to its native form, so he is fully convinced of the alien threat and his probable need for Vers’s help.
Vers faces the possibility that Fury himself has been replaced by a Skrull, and she checks by asking him questions about his childhood and personal life. He answers, she is satisfied, and quips a little.
How did this exchange prove him human? Vers has only just met Nick Fury. She knows nothing about his early or personal lives. The answers he gave her could have been totally made up. As far as she knows at the end of this conversation, he still could be a Skrull, right?