同学你好，该知识点来自沪江网校《Hitalk口语【外教1V1】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好，

in和on都可以使用~

表示在“在操场上”，playground前面通常用介词in，有时也用介词on。
如：
The children were skipping in the playground (on the playground). 孩子们在操场上跳绳。
Sam pushed me over in the playground (on the playground). 萨姆在运动场上把我推倒了。
There were children fighting in the playground (on the playground).
有小孩在操场上打架。
The children were running about in the playground (on the playground).
孩子们在运动场上跑来跑去。

现在我们常说 in the playground ，很少说 on the playground 了~
但经常会说 on the ground （在地上）。

希望以上能帮助到同学~如果还有其他问题，欢迎同学继续在答疑区提问，祝同学在沪江学习愉快！