We have bought two boxes of apples for the coming party.

你好,
为你
two boxes of apples 两箱苹果
boxes 和 apples 都是可数名词,所以用复数形式.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
祝你学习进步,更上一层楼!
不明白请及时追问,满意敬请采纳,O(∩_∩)O谢谢