1. They are familiar with the term "second breakfast".
2. "Pajamas Monday!" is a thing.
3. Their birthday is a "school holiday".
4. They have friends of differing ages.
5. They study sprawled out on the carpet or curled up on the couch rather than sitting at a desk.
6. They go to the bathroom whenever they want without asking for permission.
7. They show up to 'school' wearing a towel cape and their classroom is a homemade fort in the living room or the backyard clubhouse.
8. They're not sure which grade they're in...
9. They groan at the mention of Saxon Math.
10. Their teacher is also the janitor, school nurse, principal, lunch lady, recess monitor, secretary, and bus driver.