Sure, here is a simple paragraph for a 4th grader about their favorite subject in school, which is history:
My favorite subject in school is history. I enjoy learning about the past and how people lived long ago. History is like a big story with many interesting events and characters. I love hearing about ancient civilizations, brave explorers, and important leaders. My teacher makes the lessons fun by telling exciting stories and showing pictures. We also get to do cool projects, like building models of old buildings or creating timelines. History helps me understand how the world has changed over time and why things are the way they are today. I always look forward to history class because it feels like going on an adventure.
This paragraph is simple enough for a 4th grader to understand and includes a few reasons why history is their favorite subject.