grown-up

Now that you are a grown-up, you must take full responsibility for your finances.

(Chinese) 既然你已经是个成年人了，你必须对自己的财务负全责。

The children tried to act like grown-ups by wearing their parents' oversized shoes.

(Chinese) 孩子们穿上父母的大鞋子，试图模仿大人的样子。