Definition
Indicates that someone is responsible for something.
用于表示某人对某事负有责任。
If they don't like the outcome, then it's on them to change it.
如果他们不喜欢结果，那么改变它的责任就在他们身上。
The success or failure of this project is on you, so please make sure to do your best.
这个项目的成功或失败都在你身上，所以请务必尽力而为。
Since you insisted on making the decision yourself, the consequences are on you.
既然你坚持自己做出决定，那么后果就由你承担。