Use this pattern in any situation where you want to explain you've done it before.

当你想解释之前已经做过某事的时候，可以在各种情形下使用这个句型。

I've already 课堂 - SpeakingMax英语口语达人

if the other person has ever done something or not done something.

对方是否做过某事。

Do you ever课堂 - SpeakingMax英语口语达人