在英语中，"让他上去"的意思可以用若干种方式表达。具体的表达方式可能会根据上下文而有所不同。

一种可能的表达方式是使用动词 "send"，例如：

Could you send him up, please? （请让他上来，好吗？）
I'll send him up as soon as he's finished. （他一完成就让他上来。）

另一种可能的表达方式是使用动词 "have"，例如：

Could you have him come up, please? （请让他上来，好吗？）
I'll have him come up as soon as he's finished. （他一完成就让他上来。）

还有一种可能的表达方式是使用短语 "ask him to come up"，例如：

Could you ask him to come up, please? （请让他上来，好吗？）
I'll ask him to come up as soon as he's finished. （他一完成就让他上来。）

总的来说，"让他上去"的意思可以用若干种方式表达，比如使用动词 "send"、"have" 或短语 "ask him to come up"。这些表达方式的用法和适用情况可能会有所不同，因此需要根据具体的上下文确定使用哪种表达方式。