“你真洋务用英语”的英文说法是“You are really good at using Engpsh”。

洋务用英语指的是使用英语来进行日常交流、工作、学习等洋务，即使用英语来处理外国事务。

例句：

You are really good at using Engpsh. 你真洋务用英语。
I can tell you are fluent in Engpsh by the way you speak. 我能听出你洋务用英语很流利。
You must have studied Engpsh for a long time to be so proficient. 你一定学了很长时间的英语才能如此精通。