Looking on the internet deeply has found these results:

on the playground is the most popular phrase on the web.

in th playground 13,760 results on the web	on the playground 121,300,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	He's hurt himself on the playground. You're like some hurt little girl on the playground. There's a tunnel on the playground. You can catch up with the other kids on the playground. You can spend pleasant hours playing miniature golf on the playground at Prati di Vizze. Last punch I took was on the playground in second grade. She fell down on the playground, that's all... The youngest visitors can enjoy on the playground or in animation program.

in th playground

13,760 results on the web

on the playground

121,300,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

He's hurt himself on the playground.
You're like some hurt little girl on the playground.
There's a tunnel on the playground.
You can catch up with the other kids on the playground.
You can spend pleasant hours playing miniature golf on the playground at Prati di Vizze.
Last punch I took was on the playground in second grade.
She fell down on the playground, that's all...
The youngest visitors can enjoy on the playground or in animation program.