形容小孩"懂事",用什么单词

intelligent 聪明的

或者

a sensible fellow
聪明人, 通情达理的人

smart

sensible；intelligent
你这样做，太不 懂事。
It is thoughtless of you to do so.

他是个聪明懂事的孩子，将来准会有出息的。
He's a sensible and clever boy, and ought to turn out well.

mature / sensible

孩子还小，可是很懂事 = The child is still young, but he's matured for his age.