Middle English is a way of speaking and writing that was used in England a long, long time ago. It was used from about the year 1100 until the year 1500. That's over 500 years ago!
Back then, people used words that sound a lot different than the words we use today. They also spelled words differently than we do now. For example, they would write the word "knight" as "knyght" and the word "know" as "knowen".
The way people talked in Middle English was also different. They would say things like "Ich am" instead of "I am" and "thou art" instead of "you are". There were also different rules for making words plural, like adding "-en" to the end of some words.
Even though it might seem hard to understand now, Middle English was very important. Many important books and stories were written in Middle English, like Chaucer's "Canterbury Tales" and the epic poem "Beowulf". These stories tell us what life was like back then and how people thought and felt.
So even though we don't use Middle English anymore, it's still important to learn about it and understand its place in history.