The Prussian language was a way that people who lived in a place called Prussia used to talk to each other a long time ago. It was a special language that they spoke just in that place, and it had its own words and rules so they could understand each other.
But, over time, people stopped speaking the Prussian language and started speaking different languages that were easier for them to understand. This happened because people moved to different places, learned new things, and wanted to talk to different people.
Now, the Prussian language is not spoken anymore, and it's called an extinct language. But some people work hard to learn about it and try to understand how it was spoken and what the words meant. This helps us learn more about the people who used to live in Prussia a long time ago, even though we can't talk to them directly.