我的成绩退步了用英文怎么说

你可以用 "My grades have decpned" 表示 "我的成绩退步了"。

来源：decpne 的意思是下降，退步，减少。

英文例句及其中文翻译：

My grades have decpned since last semester.
我的成绩自上学期以来已经退步。

There has been a decpne in her performance at school.
她在学校的表现有所下降。

His grades have gone down due to lack of effort.
由于缺乏努力，他的成绩已经下降。