在操场后面怎么说英语

In English, you can say "behind the playground" to describe the location of something that is located behind the playground. For example, you might say:
"I left my backpack behind the playground when we were playing soccer."
"There's a tree with a tire swing behind the playground."
"The janitor's shed is located behind the playground."
Alternatively, you can also use the preposition "at the back of" to describe the same location. For example:
"I left my backpack at the back of the playground."
"There's a tree with a tire swing at the back of the playground."
"The janitor's shed is located at the back of the playground."