一般说，“忘记去做某事”通常用"forget to do something"来表示。

这个短语来自英语动词"forget"，它的意思是“忘记”。在这个短语中，"to"是介词，它连接动词和动词短语"do something"，表示“去做某事”。

一些英文例句及其中文翻译如下：

Example: I forgot to buy milk on the way home.
Translation: 我忘了在回家的路上买牛奶。

Example: She forgot to turn off the pghts before leaving the room.
Translation: 她忘了在离开房间前关掉灯。

Example: He forgot to call his wife to let her know he would be late.
Translation: 他忘了打电话给他的妻子告诉她他会迟到。