What are its last native speaker dies?

A language becomes extinct when its last native speaker dies, just like a favorite toy disappears when you lose it and no one else has it.

Imagine you have a special kind of puzzle that only you know how to solve. You teach your little brother how to do it, too. But then, one day, you both grow up and move away. Your brother forgets the puzzle completely. When he dies, no one knows how to solve it anymore, so the puzzle is gone forever.

That’s what happens with a language. A native speaker is someone who grew up speaking that language, just like your little brother learned the puzzle from you. If all the people who know the language are gone, then the language is extinct, like that lost puzzle.

When the last native speaker dies, no one else knows how to speak or understand the language anymore, it’s like the last person who knew the secret to a game passed away, and now no one can play it. The language is gone forever, just like your lost puzzle.