constructive
adjective uk/kənˈstrʌk.tɪv/ us/kənˈstrʌk.t̬ɪv/
C1 建设性的；有益的；有用的；积极的
If advice, criticism, or actions are constructive, they are useful and intended to help or improve something.
She criticized my writing, but in a way that was very constructive. 她批评了我的作品，但是以一种非常建设性的方式——我受益匪浅。
If you don't have anything constructive to say, it's better to say nothing. 要是你没什么有用的话要说，最好保持安静。
Opposite: destructive