I will palying computer before you come back

首先你的句子有点问题！ 要不就是 i will be playing computer before you came back 意思是在你回来之前我将正在玩电脑！要么是i will play computer before you come back !意思是在你回来之前我将玩电脑

你回来之前我玩电脑.

你回来之前我玩电脑

这句话是错的吧
will 后面 怎么能用playing

原句就写错了
i will play on computer before you come back.

其实最常见的是I will be playing on computer before you come back.
你回来前我会玩电脑。

以上