he's been collecting matches since he was ten years old.

问题描述:

he's been collecting matches since he was ten years old.
为什么是He’s been 、、、?
这是什么意思呀?
不是应该是 has been 吗?

这里的He’s been 就是has been 的缩写,翻译:【从他十岁的时候,他就一直在收集火柴】.