Hey kiddo! Have you ever heard of the word "nostratic"? Well, it's a really fancy word that describes a group of very old languages that are related to each other.
It's like when you find out that your friend's mom and your mom used to be besties in their own childhood. They may have grown up and changed a lot, but they still have a lot in common because of their past friendship. Similarly, these languages have similarities in their vocabulary, grammar, and structure because they share a common ancestor language from a long time ago.
Experts who study linguistics (which is the science of languages) believe that the nostratic language family includes languages from different parts of the world such as Europe, Africa, and Asia. Some of the languages in the nostratic family include Proto-Indo-European, Proto-Uralic, Proto-Altaic, and Proto-Afroasiatic.
But just like how people can't remember their whole life story from when they were babies, we can't exactly "hear" what the original nostratic language sounded like because it was spoken so long ago. Instead, linguists have to study ancient texts and documents to figure out how some of the words and grammar might have been back then.
So basically, nostratic languages are a special group of languages that are related to each other because they come from the same ancestor language a very long time ago. Cool, huh?